Tag Archive for safe

FAQ-Are there other pets that can live with hermit crabs?

In 2009 we introduced isopods to our crabitats.

In 2009 we introduced isopods to our crabitats.

The list of critters that can safely exist with hermit crabs is fairly short.


Isopods – beneficial tank cleaners
Springtails – beneficial tank cleaners
Food/soil mites – harmless


Fiddler Crabs/Halloween Crabs – aggressive diggers and are likely to eat molting hermit crabs.

Fiddler and Halloween crabs are aggressive diggers

Earth worms, beetles, centipedes, crickets, praying mantis, roaches: May stress each other, over populate, disrupt/harm/ kill/ eat molters. Crabs may harm /kill them. May carry/spread disease/parasites, especially with over population.

Centipedes – venomous
Millipedes – poisonous 

Snails – Hermit crabs can kill snails

Frogs/Lizards – could harm each other, different habitat needs

Fish – inappropriate water for a fish

Ask Milo – Is beach sand safe for hermit crabs?

Laureen asks:

I purchased a little crab at the wildwood boardwalk a few days ago. Yikes, I bought everything wrong ( now that I am doing my research after the fact). So… I rushed out and bought a 10 gal tank to get the little guy out of that cutsie boardwalk cage and off those dyed stones. Ive also ordered a recommended substrate, but it will take time for the handling and shipping process to get here. I live a short distance from the Atlantic Ocean (8 Miles) and am wondering if it would be ok to go to the ocean and grab some wet sand next to the surf and use that in the meantime until the substrate gets here. …And if this is acceptable, would you recommend mixing the substrate with the beach sand?

Hi Laureen,

If it’s the only sand you can get right now then yes get some sand, take it home, wash and bake it. Many crabbers use playsand or a mix of playsand and coconut fibre if they can’t get beach sand. Do a google for ‘hermit crab safe playsand’ for some ideas of brands.

I’ve used sanitised beach sand myself without any problems.

Please make sure it’s legal to collect beach sand before doing so. In some areas it is prohibited.

Your friend in a pinch,

Edible flowers for hermit crabs

Safe flowers for hermit crabs

Edible flowers for hermit crabs

The information that was used as a basis for this article was intended for humans not hermit crabs. We have adapted the list of edible flowers to what we believe is safe for hermit crabs. Some may be safe for external remedies but not for consumption.

Written by Julia Crab Monday, 23 May 2005

Did you know that flowers are good for crabs? They contain vitamin C as well as vitamin A and many of the pigmentation substances such as beta carotene. As there has been no study done on the nutritional content of flowers, much of their value remains a mystery. But crabs will enthusiastically eat flowers from this edible flower list, and prefer them as they wilt and die. Dead flowers are a particular favorite!

Before offering flowers, be sure to check that they have not been sprayed with pesticides or other chemicals, and that they’ve been fed organic plant foods. Otherwise they will not be healthy for your crabs to eat. I frequently buy bouquets of edible flowers from the organic farmer’s market near my home.

The flowers can be frozen or put in a food dehydrator as well. In fact, my crabs seem to prefer the taste of a thawed rose to a freshly wilted one.

Here is our edible flower list. Read the article at the end to be certain of which parts of a plant to use.

Borage blossoms (Borago officinalis)
Calendula flowers (Calendula officinalis)-Also known as “pot marigolds”
Carnation (Dianthus caryophyllus)
Chamomile (Matricaria recutita)

Clover (flowers, leaves)
Daisies (Bellis perennis)
Dandelion (Taraxacum officinale) (flowers, leaves, roots)
Day lilies (Hemerocallis)
Elderberry flowers (Sambucus canadensis)
Gladiolus (Gladiolus spp.)
Hibiscus (Hibiscus rosa-sinensis)

Honeysuckle flowers (Japanese Lonicera japonica)
Impatiens (Impatiens wallerana)
Jasmine (Jasmine officinale)
Johnny-Jump-Up flowers–(Viola tricolor)
Lilac (Syringa vulgaris)
Milk thistle (Silybum marianum)
Nasturtium (Tropaeolum majus)
Pansy (Viola X Wittrockiana) (flowers and leaves)
Passionflowers (Passifloraceae – passion flower family)

Prickly Pear (flowers and cactus)
Rose (Rosa spp)
Sage (Salvia officinalis)

Squash blossoms
Sunflower (Helianthus) (flowers, leaves, seeds)
Violet (Viola odorata)

Other herb flowers-The tiny flowering blooms of the following spices are edible: anise, basil, bee balm, chives, coriander (cilantro), dill, fennel, garlic, oregano, rosemary, and thyme.


Edible flowers often can be found at local farmer’s markets and gourmet grocery stores. Check with the vendor to be sure that they were organically grown. There are approximately eighty different flowers that can be safely used as food. The most enjoyable way to get these interesting additions to the diet of your family and your parrots is to grow your own!


Common edible flower varieties should be chosen for your first flower gardening adventure. Carefully follow planting, watering, and fertilization practices for garden flowers. Only organic pesticides should be used. Separate growing areas should be used for the growing of ornamental flowers requiring pesticides. Do not plant other annuals or perennials in the same area as edible flowers since pesticides from ornamentals could contaminate the edible varieties. Some gardeners plant their edible flowers indoors in sunny kitchen windows and under grow lights to avoid pesticide contamination.


As much as crabs enjoy the variety and the visual stimulation of flowers in their diet, it is as essential that we learn the difference between toxic and non-toxic varieties, as it is to use only untreated flowers. One can use a good reference book on edible flowers, available in local libraries and online. Do not use flowers from florists, nurseries or garden centers. Unless otherwise stated, these flowers have almost certainly been treated with pesticides which were not intended for food crops. Chemicals are used in all phases of ornamental growth and these chemicals are unsafe for human or parrot consumption. Flowers picked from the side of the road never should be eaten by human or parrot. Highly poisonous herbicides are used to eliminate weeds and plants bordering roadways so roadside flowers can be deadly fare. One of the best books for identifying safe flowers is Thomas S. Elias and Peter A. Dykeman’s Edible Wild Plants: A North American Field Guide (Sterling Publishing Company).



Flowers The Bach Flower remedy system of healing was developed by the British physician, Dr Edward Bach, in the 1930s. The remedies are based on the belief that flowers have healing properties. Flower essences are prepared by the infusion methods and are used for the purpose of removing negative emotions that can affect health and lead to disease. Bach Flower remedies are prepared from the non-poisonous flowers of certain trees, plants and shrubs. They are non-toxic, non-addictive, and can be taken by people and pets of all ages. If these remedies do in fact have healing qualities, perhaps the fresh non-toxic flowers would have a similar effect. Examples of the healing qualities of edible flower remedies are honeysuckles (pictured) for homesickness, nostalgia, and sadness as well as impatiens flowers for irritability, impatience, nervous tension, and muscular pain.


Flowers Aloe Vera Flower, Basil, Blackberry, Bleeding Heart, Borage, Calendula, California Wild Rose, Chamomile, Chrysanthemum, Corn, Dandelion, Dill Flower, Echinacea, Evening Primrose, Garlic, Hibiscus, Iris, Lavender, Milkweed, Mullein, Nasturtium (pictured), Peppermint, Pomegranate, Red Clover, Rosemary, Sage, Sunflower, Violet, Yarrow, Yerba Santa.


There are many more flowers that are poisonous than are edible.The use of botanical names is important due to the fact that common names vary in different regions of the country. Two plants may be known by the same common name while one is toxic and the other is edible. The following is only a partial list of the most common toxic flowers and their botanical names:

* Anemone or windflower (Anemone spp.)
* Autumn crocus (Colchicum spp.)
* Azalea and rhododendron (Rhododendron spp.)
* Buttercup (Ranunculus spp.)
* Clematis (Clematis spp.)
* Daffodil (Narcissus spp.)
* Delphinium or Larkspur (Delphinium spp.)
* Foxglove (Digitalis purpurea)
* Hyacinth (Hyacinthus orientalis)
* Hydrangea (Hydrangea spp.)
* Iris (Iris spp.)
* Lantana (Lantana camara)
* Lobelia or Cardinal flower (Lobelia spp.)
* Marsh marigold (Caltha palustris)
* Morning glory (Ipomoea spp.)
* Oleander (Nerium oleander)
* Periwinkle myrtle and vinca (Vinca spp.)
* Wisteria (Wisteria spp.)

Additional Resources:

Book recommendations:
“Edible Wild Plants: A North American Field Guide” by Thomas S. Elias and Peter A. Dykeman (Sterling Publishing Company).

“Edible Flowers: From Garden to Palate” by Cathy Wilkinson Barash (Fulcrum Publishing, 1993, 1995 $22.95)

Winged Wisdom Note: Carolyn Swicegood is a devoted fan of Eclectus parrots. Her aviary, The Land of Vos, specializes in the Vosmaeri subspecies. Carolyn has written for a variety of magazines and currently serves as Associate Editor of “Watchbird” magazine published by the American Federation of Aviculture. http://www.birdsnways.com/wisdom/ww38eii.htm

Special thank you to Vanessa Pike-Russell for locating and supplying the article.

Ask Milo – Can two different size hermit crabs live together?

Froggy Kisses writes:
Dear Milo , My crab Crab Cakes has sadly passed away recently and my other crab Sebastion seems depressed . My sister also has a crab but he is about 10 times larger than Sebastion . Will her crab Bam Bam hurt Sebastion ? And besides him interacting with Bam Bam is there anything I can do to help ?
Dear Froggy Kisses,
I am so sorry to hear about your Crab Cakes dying. 🙁 While some people may disagree there is no reason a large crab would harm a small crab. Think about how hermit crab gather in huge groups in the wild… we don’t separate ourselves into colonies based on size! We all hang out together and Sebastion and Bam Bam can definitely be friends.  Hermit crabs are not true hermits and absolutely enjoy the company of other hermit crabs so long as there is enough space in the tank for everyone.
Your friend in a pinch,

People food for hermit crabs

Plain popcorn is a favorite snack

Plain popcorn is a favorite snack

Aside from the obvious flowers, plants, leaves, fruits and vegetables, there are some other people foods that can be safe to feed to your hermit crabs. This is not an exhaustive list but the most common we come across:

Popcorn – plain (no salt no butter). If you don’t care for plain popcorn you can always buy a small quantity of kernels and pop two or three in the microwave using a paper bag.

Hot dogs – go for all natural and only feed occasionally due to nitrates and other chemicals. No known research on their effects but you should limit the chemicals you are feeding to your hermit crabs in general. Be aware, hermit crabs can get downright piggy over hot dogs and may attempt to bury it for later. This will make your tank moldy and super stinky gross.

Babyfood – this is good if you have a hermit crab that has lost a pincer and is having trouble eating
Unsalted pretzels
Peanut butter – natural, no salt added
Honey – best served in a small dish that the crabs can’t climb into, otherwise you will have a very sticky hermit crab.
Bones – remove the meat if any seasoning was used and then take a hammer and smash the bone so it’s open and the marrow is exposed
Unsalted crackers
Plain cereal – no sugar added
Plain rice cakes
Eggs – raw is probably ok but will be super messy, better to go with scrambled
Egg shells – crushed to a fine powder this is a good source of calcium
Protein – unseasoned: fish, chicken, turkey, beef, pork, tofu
Sardines – look for natural with no additives

Which types of moss are safe for my hermit crabs?

Hermit crabs enjoying some moss while their tank is being cleaned!

What kind of moss is safe for hermit crabs? Photo credit – Stacy Griffith

Hermit crabs love moss! Not only is it a great way to create and maintain humidity but your crabs will burrow in it and even eat it. They key is to select safe moss. This page should give you a starting pointing for determining which types of moss are safe for your hermit crabs.

There are over 1200 types of moss so it would be impossible to address all of them. Listed below are the most commonly encountered types. In all instances you are looking for 100% natural, chemical free, dye free moss. When collecting your own live moss, know what you are collecting and do not collect from areas that may have been sprayed with chemicals or pesticides or contains pine needles/pine cones.

Unsafe Moss

Peat Moss (Sometimes this is labelled sphagnum peat moss)
ladybug15057 answered:

Doing a quick search, here are a couple of links about Sphagnum moss:

“Don’t confuse sphagnum moss with sphagnum peat moss. Sphagnum moss and sphagnum peat moss are not the same product. Sphagnum moss is used in the floral industry to line wire baskets and make wreaths. It is the LIVING moss that grows on top of a sphagnum bog. This is a safe moss. Sphagnum peat moss is used as a soil conditioner by gardeners. It is the dead material that accumulates in the lower levels of a sphagnum bog. Harvesters of the horticultural peat moss remove the top few inches of the live sphagnum moss before harvesting the peat from the lower levels of the bog.

There has also been some confusion about which of the two is actually the source of a fungal disease called Cutaneous Sporotrichosis, which according to Gerry Hood of the Canadian Sphagnum Peat Moss Association, is causing some concern within gardening circles. Sporotrichosis is a chronic infection identified by ulcerous skin lesions and is caused by coming in contact with the fungus, Sporothrix schenckii. Research has found no cases of sporotrichosis being transmitted in sphagnum peat moss. However, the fungus Sporothrix schenckii,does live in the top, living portion of the bog that is removed before peat harvesting.”





Peat moss can also acidify its surroundings by taking up cations such as calcium and magnesium and releasing hydrogen ions.

Sue Latell answered:
Cypress is a conifer. Coniferous wood/needles are toxic to crabs when ingested. Crabs typically graze on their substrates, making cypress a bad substrate. Cypress mulch according to my herp expert is really best for reptiles that are carnivorous. Cypress has uses only in EXTERNAL application, for most mammals and other animals it has toxic properties, and depending on the species of cypress, the most common is arsenic.

Spanish Moss (sometimes called Cypress moss) is often treated with chemicals

Reindeer/Caribou (lichen) Moss – usually dyed and therefore unsafe.

Safe Moss

Frog Moss/Pillow Moss
Sold by Zoo Med

Zoo Med Frog Moss

Zoo Med Frog Moss

Pillow Moss

Pillow Moss

Completely natural frog moss for use with frogs, toads, salamanders, garter or green snakes, and all other moss environment species. Use as a top substrate or decorative accent in vivarium/terrarium applications.

Frog Moss (also called “Pillow Moss”) will come back to life and grow in proper terrarium conditions.
A beautiful, decorative living moss to accent your naturalistic terrarium.
Increases humidity in terrariums making it perfect for all high humidity loving species of reptiles or amphibians.

Additional Information:
Zoo Med’s Frog Moss can be washed and reused several times before needing to be replaced with new moss.

Beaked Moss

Zilla Beaked Moss

Zilla Beaked Moss

100% natural terrarium moss is great for amphibians and reptiles that inhabit moist environments. The moss holds moisture, generating higher levels of humidity that is beneficial for tropical and forest species. Ideal for Chameleons, Frogs, Green Anoles, Rainforest Geckos, Salamanders & Newts.

• Holds Moisture
• Provides a Realistic Setting for Reptiles and Amphibians
• Completely Natural (no dyes or chemicals)

Moisture stability with natural beauty
From the lush coniferous rain forests of Oregon, we harvest a moisture-loving moss that tropical reptiles thrive in. Its natural moisture retention properties keep humidity levels uniformly high, while forming a lovely green carpet that’s the closest thing to home for rainforest reptiles. Looks great, and your favorite pet will love having it under foot! Since it’s 100% biodegradable, mulch it into your garden for natural disposal.

Ideal for Chameleons, Frogs, Green Anoles, Rainforest Geckos, Salamanders & Newts.
Zill Beaked moss

Flukers makes dyed and undyed moss. Both are listed as all natural. They are easy to tell the difference though. The undyed is perfectly safe, the jury is out on the other.

Hiawatha Moss

Hiawatha Moss

Hiawatha Moss

Hiawatha moss is grown naturally in the Pacific Northwest. 100% natural terrarium moss is great for amphibians and reptiles that inhabit moist environments. The moss holds moisture, generating higher levels of humidity that is beneficial for tropical and forest species.

Sheet (Hypnum) Moss

Sheet Moss

Sheet Moss

Sheet moss or Hypnum moss is transplantable and may be a moss you could coax into growing live in your crabitat.
Exo Terra is selling Forest Moss which is actually Plume moss and I’ve used it in my tank with no issues.

The Exo Terra Forest Moss Tropical Terrarium Substrate is real compressed moss grown in tropical Asia. This ecological substrate is ideal for increasing humidity in the terrarium and is totally safe for frogs, salamanders and burrowing or digging animals. The Exo Terra Forest Moss Tropical Terrarium Substrate is extremely absorbent and is recommended in humidifying shelters such as the Exo Terra Snake Cave or Reptile Cave. It is also an ideal egg-laying or incubation medium.

ExoTerra Forest Moss (Plume Moss)

ExoTerra Forest Moss (Plume Moss)

Sphagnum moss
Used in the floral industry to line wire baskets and make wreaths. It is the LIVING moss that grows on top of a sphagnum bog. This is a safe moss.

Don’t forget the moss – Naturally Crabby

Safe and Unsafe Wood

Wash and bake the wood.

Safe and Unsafe Wood for Hermit Crabs

Written by Julia Crab (Kerie Campbell) Wednesday, 28 September 2005

Here follows a list of woods that can be used safely in a hermit crab environment. These are non-toxic woods that won’t hurt them if eaten. This list, as all the others, is not in any way complete, and will be expanded as new information is received.

Cholla or Choya wood
Cork bark
Cypress (swamp variety, taxodium species) **not a suitable substrate!
Grape vine
Maple/Japanese Maple

Unsafe Woods

Bitter Almond
Black Locust
Cherry Laurel
Evergreen of any kind (pine, cedar, redwood, etc.)
Walnut (added 2/2018 after consulting with invertebrate veterinarians)

As an alternative to the pine half logs you see for sale for reptiles, Petco is now selling fake (as in non wood!) pine half logs. Joy!

Fake wood pine half logs- safe for hermit crabs

Fake wood pine half logs- safe for hermit crabs

Fake wood pine half logs- safe for hermit crabs

Fake wood pine half logs- safe for hermit crabs

Guide to bugs you might find in your crabitat

originally written by Jedediah


Insects have six legs and three body parts that are usually clearly visible, the head, the thorax (the breast) and the abdomen. Most of them have wings, although those might not be clearly visible, some insects can hide them in a sort of pouch on their back (like earwigs) and some insects have no wings at all. The vast majority of insects that you might find in your crabitat are beneficial, harmless or a nuisance at most. Usually you can get rid of them by doing a deep clean.

Common insects are:

Booklice aka Paperlice



Very often described as walking grains of sand, booklice are tiny and usually white to grey in colour. They are often hard to get rid of, probably because they can live in the rest of the house, too and quickly return to the crabitat where they find ideal conditions. They are harmless and even beneficial because they feed on mold and fungi.
Interesting fact: there are no male booklice, the females “clone” themselves, they are all more or less genetically identical.

2010 Booklice infestation

2010 Booklice infestation








Springtails are white, brown, green red, yellow or grey and very small, no bigger than 1/8 inch. They can hurl themselves in the air with a forklike tail they hold under their body, but they have no wings. Springtails are often found in flower pots and they need a humid atmosphere to survive, so the crabitat is ideal for them. They are beneficial because they will feed on crab poop, leftover food and other decaying material, they are excellent cleaners.
Interesting fact: Springtails are among the oldest insect species, they have been around for at least 400 million years.



Incredible skin helps springtails to keep dry underwater and always stay clean



Fruit flies or Drosophila

Drosophila- Fruit fly

Drosophila- Fruit fly

You probably know them, these are the flies that turn up whenever a piece of fruit is left for too long. The most common species is Drosophila melanogaster, around 2 mm in size, usually red eyes and a brownish colour (other species are a bit bigger or smaller, up to 4 mm). They feed on decaying fruit and breed rapidly (two weeks between generations) and can become a nuisance in the crabitat, although they are not harmful. To get rid of them, place a glass with wine, beer or fruit juice mixed with vinegar and a drop of dish liquid next to the crabitat, the flies will drown in the liquid. It’s best to stop feeding fruit for that time so that the larvae won’t find any food.
Interesting fact: Fruit flies mutate easily and you can breed really weird flies in a short time (no wings, small wings, white eyes, no eyes ect.)


Humpbacked Flies or Phorid Flies



Photos of Phorid Flies
This article states that Phorid flies do indeed infest many small invertebrates including hermit crabs: http://bugguide.net/node/view/14163

Excerpt from this page:
Other Common Names
Humpbacked Flies, Coffin Flies
Explanation of Names
Phoridae Curtis 1833
Scuttle Flies: refers to their habit of running quickly in short bursts, followed by short pauses; Coffin Flies: larvae can be a pest in mausoleums, entering coffins and feeding on the bodies inside
376 described species in 50 genera in North America (half of the fauna are Megaselia), >4,200 described species in >300 genera total(1), and many times that number undescribed(2)
Adult 1-7 mm (many 2-4 mm)
Tiny black, brown, or yellowish flies with a humped back, a low small head, and dark eyes; costal vein extends only about halfway along anterior wing margin; two strong longitudinal veins anteriorly (in costal area), and 4-5 weak veins posteriorly, not connected by cross-veins; hind femora enlarged and flattened, and hind legs long; antennae appear 1-segmented
The way of life of most species is unknown. A few common, synanthropic species, especially Megaselia scalaris, Dohrniphora cornuta, Megaselia rufipes, and Puliciphora borinquenensis, live in almost any type of decaying organic material. Larvae of D. cornuta often build up to huge populations when sewer pipes break and nutrient-rich water soaks into the soil; adults emerge in swarms through drain pipes in affected houses. The most commonly noticed species of phorid is M. scalaris, which is found in a number of filth-fly situations, and also infests nearly every type of invertebrate and small vertebrate cultures, such as insect zoos, tarantulas, lizards, snakes, hermit crabs, etc.
Most species, however, are probably specialized scavengers, predators, parasitoids, and even true parasites. Many Megaselia species are found in fungi, some feeding on the fungus (including a few commercially important pests), others probably feeding on sciarid larvae. Many species are found in buried carrion, away from competition from blow flies and other agressive species. One such species, the coffin fly, is found commonly on buried human bodies. Small invertebrate carrion, such as snails, slug, and dead insects, are also breeding sites for phorids. Species of the genus Anevrina are found in the burrows of mammals, probably as scavengers.
Many species are associated with ants, as commensals in ant nests or as parasitoids. The largest group of ant-parasitoids, Apocephalus, are known as ant-decapitating flies because they develop inside the ant’s head, and some species cause the ant’s head to fall off, sometimes before the rest of the body stops moving. Most North American Apocephalus attack ants in the genera Camponotus and Pheidole, but other hosts are used here and elsewhere. Another ant-parasitoid genus is Pseudacteon, whose South American species are being used in attempts to biologically control imported fire ants (since the native Pseudacteon are not doing the job!).
Other parasitoid genera attack millipedes (phorid genus Myriophora), fireflies and cantharid beetles (some Apocephalus), bees (some other Apocephalus), scale insects, beetles, and probably many other hosts we do not know about.
Some phorids have wingless or short-winged females. Some of these are commensals or parasitoids associated with ants, others are scavengers that are apparently not associated with ants.
-Brian Brown”

Controlling phorid flies infestation

They look very much like fruit flies, but if you take a closer look, you can see a hump. Apart from that, they can be recognized by the way they run around: very fast, always stopping after a short distance and very reluctant to fly. Humpbacked flies are the only insects that have been found in crabitats that can be harmfull to the crabs, at least I haven’t heard of any other. The adults and larvae can feed on almost anything including flesh, so if a crab has an open wound the larvae are able to get into the wound and eat the crab from the inside out. Some species are able to lay their eggs into healthy animals, but those are parasites of a certain species and as far as I know, no phorid fly preys on land hermit crabs specifically. To get rid of them, do a deep clean, bake or boil everything, bathe the crabs and I recommend keeping the crabs in an ISO tank that’s easy to clean for six weeks to make sure there are no eggs or larvae left. Clean the ISO every week (change substrate and hiding places, boil or bake the hiding places you want to use again) and make sure the food doesn’t spoil.

Interesting fact: Phorid flies have been known to survive by eating shoe polish – you somehow have to admire a bug that’s so adaptive

http://ohioline.osu.edu/hyg-fact/2000/2144.html (dead link)


Fungus gnats

Fungus gnat

Fungus gnat

Fungus gnats are small (2,5 mm), black flies. Both the adults and the larvae feed on decaying and living plant matter, the adults eat pollen, too, and they are harmless to the crabs, but can become a pest when they multiply too much. To get rid of them, you can use yellow sticky traps. Those are sticky on both sides and can be attached to the lid of the crabitat where the crabs cannot reach them.


Silverfish and Firebrats

Silverfish Firebrat

Silverfish Firebrat

Those are rarely found in crabitats, but I will include them anyway. Silverfish are often found in bathrooms, firebrats need a high temperature to breed and are sometimes found in bakeries and other warm places. Both look similar, 1/3 to ¾ inches long and carrot shaped without wings. Silverfish are silver in colour and really look a bit like fish. Firebrats are hairy and often have dark grey stripes on their body. Both feed on almost anything at all, including cereals, fish food ect. They are harmless and won’t breed in the crabitat because it’s too humid and too cool for the firebrats and probably too hot for the silverfish, so they will disappear eventually. They mostly get into crabitats by chance.
Interesting fact: Both can survive and even thrive on a steady diet of wallpaper, tissue paper or similar things. Like springtails, they have been around for a very long time.




There are more insects that can be found in your crabitat, especially small flies and other tiny insects living in the soil, but those are the species that people have found very often and that were positively identified. If you find something else, try to take a picture of make a drawing so that the bug can be identified.


Arachnids are such bugs as spiders, scorpions, mites and other bugs related to spiders. They have two body parts, the thorax and the abdomen, no wings or antenna and eight legs.


There are thousands of species of mites and it’s extremely hard to identify them. They come in all colours (white, grey, black, brown, bright red ect.) and many sizes. Only comparatively few species are harmful for the crabs. The rule of thumb is: if you find them in the food dish or the rest of the crabitat, they are probably harmless. If you find them on the crab, especially on the joints, the abdomen or the mouthparts, they are predatory and harmfull. A deep clean will get rid of the harmless mites, for the predatory ones you will need to bathe the crabs in salt water or you might even need to pick off the mites because they have claws on their legs to hold onto their prey.

Interesting fact: Some mites feed on pollen and hitch rides with hummingbirds, racing up the beak and then down again into a new flower. Others hitch rides with flying insects to reach new plants and some not only hitch a ride, but also suck the haemolymph (insect blood) on the insect that’s carrying them. Many species change their dietary habits depending on their age.

Click on the links at the bottom to see pictures of mites hitching rides with insects:


Other mite pictures:

Bookscorpion or Pseudoscorpions



A rare guest in crabitats that sometimes comes with moss or leaf litter is the bookscorpion. They look like tiny (1-4 mm) scorpions, but have no tail and are absolutely harmless unless you are a springtail or a fruit fly.

Interesting fact: One species, Chelifer cancroides, does live in books and this species gave the whole order its name. They dance with each other during mating and they build a small nest from grains of sand, moss and silk. The females produce a nourishing substance for their babies, so in a sense they nurse their babies.


Other bugs you might find




Woodlice, also called pillbugs, sowbugs or rolypolys, are the only crustaceans that live permanently on land without any contact to water. They need a humid atmosphere to breathe, that’s why they are sometimes found in crabitats. Woodlice are harmless and feed on decaying plant matter. They are often used as tank cleaners with reptiles, phasmids and other animals.

http://www.geocities.com/CapeCanaveral/Hangar/7649/wlice.htm (DEAD LINK)


Millipedes and Centipedes





Both belong to the Subphylum Myrapodia (this means “numerous feet”) of the Phyllum Arthropoda (“joint-legged”), which insects, arachnids and crustaceans belong to, too. Millipedes (“with a thousand feet”) have two legs on either side per body segment, centipedes (“with a hundred feet”) only one. They sometimes turn up in crabitats and come from moss, leaf litter or with live plants. Millipedes are vegetarians that feed on decaying plant matter, centipedes are predators. The centipedes you might find in your crabitat are very small and are no danger to the crabs.

Interesting fact: Millipede males of some species can breed only after every second molt.


Bugs that help getting rid of other bugs

You can purchase predatory mites or insects that will feed on some bugs in your crabitat and then die when they find no more prey. This is a efficient and absolutely crab-safe method to get rid of bugs, without stressing the crabs by doing deep cleans ect.

Here’s one website that offers such bugs:

FAQ What foods are good and bad for hermit crabs?

Hermit Crabs are beach scavengers and they can and will eat a wide range of things. General rules:

Photo by bird1234 (youtube)

FAQ What foods are good and bad for hermit crabs? – Coenobita perlatus eating garbage – Photo by bird1234 (youtube)

Avoid chemicals, pesticides, table salt, moldy foods, plants that are toxic to animals.

For hermit crab nutritional needs and the foods that provide them, download the nutritional food chart as a PDF by clicking in the gray box below.

Hermit Crab Nutrition Table
Hermit Crab Nutrition Table
270.6 KiB

Written by Kerie Campbell

Fruits – Fresh or Wrinkly? I’ve read alot about fresh fruits being in their diets, which I use alot of BTW. But I’ve read alot about people putting in fruits that are old and wrinkling up. Is one better than the other?

Answer by: Kerie
Posted: Fri Mar 04, 2005 7:52 am
The crabs like it fresh, and they like it wrinkled. Mine also like stuff that’s gone mushy from being thawed after freezing. Alternating fresh and older fruit is a good way to vary their diet. The sugars and other compounds like terpenoids in the fruit will tend to change composition and break down for different flavors as the fruit ages. If it’s citrus fruit, though, you should always let it sit until it is wrinkly. The peels contain substances like limonene that act as insect repellents. Limonene breaks down quickly in the fruit peel as it ages, so letting it go wrinkly makes it much more attractive to the crabs. Citrus has compounds in the pith and stringy stuff that are extremely beneficial to crabs, such as beta carotene, and so citrus should be offered them on occasion, in order to promote a healthy diet.

What foods are good for hermit crabs?

Almonds, crushed
Amaranth (Ancient grain – calcium)
Anchovy oil
Apple and natural, unsweetened apple sauce
Barley (calcium)
Bell peppers (red, yellow, orange, green or purple)
Bee pollen
Blackberry leaves
Bone Meal (no additives, preservatives, sold as a supplement for people)
Broccoli and leaves
Brown rice, soy, wheat or 7 grain cereal
Brown rice
Carnation flowers
Carrots (carotenoids)
Carrot tops (vit. E)
Cat Tails
Cauliflower and leaves
Celery leaves
Chamomile flowers
Chicken bones
Chicken, cooked and unseasoned (smash the bone for marrow access)
Cholla wood
Clover blossoms and leaves
Coconut and coconut oil
Cod liver oil
Collards (calcium)
Cooked eggs
Cork bark
Corn (on the cob, too)
Cranberries (dehydrated)
Cuttlefish bone, powdered
Dandelion flowers, leaves and roots
Egg, scrambled or soft boiled
Extra-virgin olive oil
Fish flakes w/out chemical preservatives
Fish Oil
Flax seeds (crushed)
Flax seed oil (small amounts infrequently)
Frozen fish food (esp. algae, krill and brine shrimp)
Garbanzos (calcium)
Grape Leaf
Grapevine (vines and root)
Green and red leaf lettuce (not iceburg; dark green)
Green Beans
Hempseed Meal
Hibiscus flowers
Hikari products: brine shrimp, krill, crab cuisine, sea plankton (no preservatives, ethoxyquin, copper sulfate)
Hollyhock flowers
Honey (organic, or at least locally produced, for anti-microbials)
Honeydew Melon
Irish Moss
Impatiens flowers
Jasmine flowers
Kelp (calcium)
Lobster with crushed exoskeleton
Marigold flowers (calendula)
Marion Berries
Mint (but not peppermint!)
Most organic baby foods
Mulberry (fruit, leaves, wood)
Nasturtium flowers
Nettle (wilted)
Oak Leaves and bark
Olive and olive oil (extra virgin)
Oysters (zinc)
Pansy flowers and leaves
Parsley (calcium & vit. C)
Peanut butter (avoid sugar, corn syrup and hydrogenated oils)
Pecan bark
Plain calcium carbonate powder
Popcorn (unseasoned, unflavored, unbuttered)
Potato (no green parts, including eyes)
Quinoa (New World grain – calcium)
Raisins (no sulphur dioxide)
Red raspberry leaves (highest bio available calcium source + vit. C and trace minerals)
Rolled Oats
Rose petals
Rose hips (high in Vit. C)
Royal Jelly
Sand dollars
Sardines (calcium)
Sea biscuits
Sea fan (red or black)
Sea grasses
Sea salt
Sea Sponges
Sesame seeds (crushed)
Shrimp and exoskeletons
Spirulina (complete protein and chlorophyll source; highest in beta carotene)
Sprouts (flax, wheat, bean, alfalfa, etc.)
Squash and blossoms
Strawberry and tops
Sunflower Seeds (crushed), flowers and leaves
Swamp cypress wood (false cypress, taxodium sp.)
Sweet potato
Tuna (zinc)
Turnip greens (calcium)
Violet flowers
Wasa All-Natural? Crispbread (Oat flavor)
Watercress (vit. A)
Wheat grass (magnesium)
Wheat (calcium)
Wheat germ (B vitamins)
Whole Wheat Couscous
Worm Castings

Other herb flowers-The tiny flowering blooms of the following spices are edible: anise, basil, bee balm, chives, coriander (cilantro), dill, fennel, garlic, oregano, rosemary, and thyme.


Beetle Grubs
Cicada exo skeletons
Feeder cockroaches
Super worms

* This food list is mainly adapted from Summer Michealson and Stacey Arenella’s book, The All-Natural? Hermit Crab Sourcebook, and expanded on by Julia Crab and others

What foods are bad for hermit crabs?

While it is true that crabs are scavengers with a wide repertoire of foods they can eat, there are many plants and foods that just should not be fed to a crab. The foods on this list are to be avoided. Some are toxic, some are insect repellents or used as insecticides, and some the crabs just won’t go near, such as lemon — lemon won’t hurt them, but they certainly won’t eat it.

Aconite (Monk’s Hood)
African violet leaves
Alder bark
Aloe vera (interferes with potassium absorption)
American Hellebore
Avocado leaves
Bird of Paradise Flowers
Bottlebrush flowers
Carnation leaves
Castor Bean
Cherimoya Seeds
Citrus (leaves and branches to be avoided; part of the evergreen family. The fruit is fine)
Compost (unless 100% organic)
Crown of Thorns
Cube Plant
Custard Apple (young fruit)
European pennyroyal
Evergreen (pine, cedar, juniper, etc.)
Golden Pothos
Green hellebore
Holly Berries
Ivy (of any kind)
Juniper Berries
Larkspur seed
Lemon Balm (Sweet Melissa)
Lemon Grass
Lucky Bamboo (Dracaena sanderiana)
Morning Glory
Oxeye daisy
Papaya seed
Parsley Seed (fruit)
Peace Lily
Pencil Tree Cactus
Pine or cedar wood or needles
Prickly juniper
Pride of China fruit
Prunus species trees (apricot, bitter almond, cherry, cherry laurel,
nectarine, peach, plum) Fleshy fruits are edible, everything else
contains a cyanide-like compound and is fatally toxic, including
seeds, wood, leaves, bark and flowers.
Red Emerald
Sago Palm
Stargazer Lily (Lilium x Stargazer)
Sweet Flag
Tea Tree
Texas Mountain Laurel (Sophora secundiflora)
Wild Angelica fruit

From: The San Diego Turtle and Tortoise Society
And other sources

We highly recommend keeping worm castings and greensand on hand and in your tank daily. Both are highly nutritious and are loved by hermit crabs.

Awesome video of a huge  gathering of Coenobita perlatus eating garbage

FAQ Is Polyvinyl Chloride/PVC Pipe safe to use in the crabitat?

FAQ Is PVC pipe safe for hermit crabs?

FAQ Is PVC pipe safe for hermit crabs?

CrabbyAbbey answered:

PVC isn’t a safe product to be used in a closed environment or with land hermits that tend to taste sample their surroundings, or really anywhere for that matter.

It’s production includes chlorine and lead and it leaches chemical gases into the air, especially in heated areas. In closed areas like crabitats these dangers are even more harmful.

My largest tank is a reef tank and removing the installed PVC plumbing opens two holes at the bottom of my tank. When I bought it 2 years ago I thought a wise way to address that was to wrap the PVC with sisal rope. It solved the problem and gave the crabs something tall and fun to climb and hang out on. Once I realized the dangers of it I removed the pipe and had the holes sealed with a small square of plexiglass.

Stacy answered:

Something I found on a bird forum:

So going off memory, basically the High Definition PVC (furniture grade) is the best. It’s been deemed safe and used to make items for children. It doesn’t contain dioxins, plasticizers or harmful metals.

What is Furniture Grade PVC?

CPVC (the cream colored PVC) is safe to use for hot and cold water, whereas PVC is only safe used for cold water. The CPVC doesn’t degrade in the sun like PVC does and CPVC also doesn’t off-gas if heated up. Heated PVC will off-gas a colorless, odorless fume which is toxic. CPVC is smaller than the PVC. CPVC goes by the outer diameter measurement whereas PVC uses the inner hollow hole size as it’s measurement.

I wouldn’t use the Schedule 40 white PVC to build anything that could possibly get too warm or be outside in the sun.

I also wouldn’t make something out of PVC that would be chewed on; like a hanging toy or foot toy. I made a shower stand out of PVC years ago, it serves it’s purpose and the birds don’t chew it.

Toxic chemicals need to be removed from schools and daycares

Polyvinyl Chloride – PVC