Ask Milo

The hermit crab advice column, Ask Milo.

Ask Milo – Finding a lost hermit crab

Hermit Crab101 asks:

My crab escaped yesterday night and I have no clue where he is I am a “newbie” to hermit crabs and have not seen him really eat anything or any bite marks in the morning. I even gave him walnuts! Still nothing So how should I find him and what should I feed him.

This happens so much we have and FAQ devoted to it: Find my lost hermit crab

We also have a starter list of things your hermit crab can eat: What foods are good or bad for my hermit crab to eat?

Good Luck!

Your friend in a pinch,



Ask Milo – Is grass a safe substrate?

Hermit crab101 writes:
I just got a hermit crab from the Jersey Board walk by surprise and I have no supplies and am saving up for more supplies but just for now is grass a good bedding for your crabbatat?
Hi Hermit Crab101!
Grass is not dangerous to a hermit crab but it is not a safe substrate. Sand mixed with coco fiber is the perfect substrate.  You can read more about substrates here: Substrates for Hermit Crabs
To get the complete list of supplies you will need check out this article: Hermit Crab Essentials Shopping List
Your friend in a pinch,

Ask Milo – Where to buy in South Caroline

Taylor writes:

where would be the best place to get a healthy baby hermit crab in south carolina near palms beach

Hi Taylor!

Unfortunately I’m not familiar with that area. I would recommend you use Google to search for privately owned pet stores in that area. Often an independent retail store will do a better job of caring for the pets they sell than say a major chain store like Petsmart or Petco.

Good luck!

Your friend in a pinch,

Ask Milo – Protecting a molter from a tank mate

Shawn writes:

What should I do for my crab gypsy she went down for a molt shortly loosing hr companion sparky? I got her a new friend just before she went down now parodite keeps trying to dig her up. I tried putting gypsy in the molting tank but she was unhappy there anyway I can tell how she’s doing? Or how can I keep parodite off the area until gypsy is ready to come up? I have a small ( gypsy) and a tiny ( parodite) in a ten gallon with 6 inches of half sand half eco earth.

Hi Shawn!

Isn’t it frustrating when you have a naughty crab on your hands? The best way to isolate Gypsy is to cut the base off of a 2 Liter plastic bottle (like pop comes in) and press it down where Gypsy is dug under. You must be gentle so as not to collapse the burrow but if you press it all the way down to the bottom of your tank there is no way Parodite can get to Gypsy. You will want to remove the cap to allow air exchange. If you aren’t sure exactly where Gypsy is you could use some plexiglass to divide the tank in half and then use another piece to lay over the substrate above Gypsy. That way even if Parodite scales the divider he/she can’t dig down.

Hope this helps!

Your friend in a pinch,

Ask Milo – Dead crab smell

Vette asks

We think our son got the hermit crab out of his cage! And we can’t find it. We are leaving going on vacation next week. If we can’t find it we know it will dead. So how do we get the smell out of our house?

Well Vette while I can’t offer any suggestions on getting the smell of a dead hermit crab out of your house I can help you find the missing hermit crab before it dies. This is actually a common occurrence and we have an article about it. Check it out:

Also register for an account and join our forum for some additional advice if the steps in that article fail.

Good luck!

Your friend in a pinch,

Ask Milo-Post Molt Shell Change

Stephanie asks:

I’ve had my hermit crabs for a few months and I have noticed a couple of things. One of my crabs molten but did not change shells, is that weird. Also, my crabs stopped moving around inside the tank. They never are active. What should I do?

Hi Stephanie!
It is a common misconception that hermit crabs must change shells when they molt. This is not true. Hermit crabs change shells when they decide it is time. A molt can trigger a shell change if the shell was very small fitting prior to molt. You can’t control when your little guys change shells so always have 4 or 5 empty shells per crab for them to choose from.

If your crabs are never active the first thing you should check is your temperature to make sure it is in within the ideal range of 72-82F. Also make sure your humidity is a proper levels. Hermit crabs are primarily nocturnal so they are the most active at night. It could be possible you aren’t awake to notice their movements.

Hope this helps!

Your friend in a pinch,

Ask Milo – Isolation tank

Gabrielle submitted the following question:
I’m purchasing two hermit crabs soon. I keep reading that I need an isolation tank, but I really don’t have the space or funds for one. Is there anything I can do for molting crabs without purchasing a whole new isolation tank? If not, do you have any recommendations on how to do it as cheaply as possible? I’ve spent so much money on their regular supplies already haha. Thank you!

Dear Gabrielle,

Setting up a crabitat can be expensive. An isolation tank can be a smaller tank that fits within your larger tank. It doesn’t need to be a full size tank. It is best if you do have a full size isolation tank, though, as new hermit crabs often need to relax after post purchase stress (PPS) and may be traumatised by interactions with other land hermit crabs. Most newly purchased crabs will either dig down and hide for a while or head to the food and water bowl and then dig down. It depends on the conditions they were in before you bought or adopted them from. They can surprise crabs that are already moulting, which would be bad.

Since you are worried about molting crabs and not new crabs right now, you can use an in place isolation. For a surface molter this can be accomplished by cutting the bottom off of a 2L plastic bottle and then placing it over the molter and pushing it down (gently!) into the substrate, all the way to the bottom of your tank if possible. This will keep tank mates from cannibalizing the molter while it is soft and defenseless. Remove the lid from the bottle top to allow air flow. If you can’t get the bottle all the way to the bottom of the tank, keep an eye out for signs of other crabs trying to burrow their way in.

Another easy isolation unit for a molting hermit crab can be a small Kritter Keeper or Living World Small Pals Pen.

Screenshot 2015-05-20 12.29.24gel_limb_recovered323sm_jpg_jpg

It has a lid to close to keep the other hermit crabs out and has enough area for some sand, scallop shell for food and another for water. When the hermit crab is finished molting you can lift the lid up and other hermit crabs may dig down to moult in it. It doesn’t take up a lot of surface area and you can put it on a second level if you have one.

Another option is a Gladware bowls that you can buy at the dollar store. The lids are thin plastic that you can poke holes in. They are a great humid hides in your tank. Another solution is to check out Garage/Tag/Yard sales, eBay, Craigslist and other online sites for second hand 10 Gallon or 20 Gallon fish tanks. They are often cheap and good to have on hand. If you are in Australia then Gumtree is also a good resource. Good luck!


Your friend in a pinch, Milo

Ask Milo – Heating Wire Cages

Hanna submitted the following question:

So I just got 2 hermit crabs and they are in wire cages. but i have the heating pad in there but i did not take off the back side to the heater baecause it will melt the plastic. Will my crabs die!
Dear Hanna,

Wire cages are not appropriate for land hermit crabs for housing. You will need to buy a glass tank. You can often find second hand glass fish tanks at Yard/Garage/Tag sales or on Craigslist, eBay and other classified sites very cheaply. Wire cages do not keep the humidity in, and as their bases can be plastic, like the one you have, it makes it difficult to heat them without melting the plastic and causing suffocation of your crabs due to the fumes!

 A glass tank with lid helps keep in the temperature and humidity. The minimum purchased should be 10 Gallon.

Plastic Kritter Keepers can be inexpensive but they have ventilation holes which can release the temperature and humidity that your hermit crab so dearly need! They are plastic and scratch easily and will heat differently to glass tanks. You would need to purchase a heater for plastic tanks. A glass tank is really the best option for new hermit crab owners. You will be able to add an appropriate amount of substrate for the size of your crabs, add driftwood trees, hang nets, add food and water bowls and dishes. Just so much more than a wire cage can offer. Most hermit crabs die in wire cages.

Your friend in a pinch, Milo


Ask Milo – Flying bugs in tank

Bri4321 submitted the following question :

There are tiny flying brown bugs in my hermit crab cage. I think that they might be gnats or fruit flies. I really need to get rid of them without hurting my crab. How do I get rid of them? Thanks so much if you can help! My hermit crab cage looks like this:

Wire Cage - Unsuitable

Dear Bri4321,

Firstly I would recommend you upgrade from the wire cage to a glass tank with lids as soon as possible. You will continue to have problems with gnats or fruit flies as they are attracted to the hermit crab food and can fly in through the gaps in the wire. There is also no ability to retain humidity or temperature without a closed enclosure. You can pick up some cheap tanks on eBay and Craigslist.

To get rid of the gnats you will need to remove the food from your wire cage, change the substrate (if you have any), change the food on a daily basis and avoid giving them foods which include wheat germ. I would avoid placing fresh fruit for the time being.Just until you have a glass crabitat. There may be gnat larvae in your wire cage so you might need to remove the hermit crabs from the cage, wash out the cage and scrub it, then give your hermit crabs a bath in water with stress coat. Gnats and fruit flies can irritate them.

I would put a towel or blanket over the tank at night when you put your food in to stop more gnats from entering the tank. I hope this helps.

‘Your friend in a pinch,

Is my hermit crab’s daytime behavior normal?

Heather submitted the following question:
My hermit crab like to explore during the day and is in a sleep-like position at night. Is that normal?

Check the substrate temperature too!

Check the substrate temperature too!

Well Heather while hermit crabs are mostly nocturnal, they are also seen being active during the day. It sounds like possibly your tank is too cold and your hermit crab is active during the day when it is warmer and lethargic at night because it’s too cool. Minimum temperature should be 75F and maximum should be 82F. Your tank should provide a range of temperatures between the minimum and maximum. It is also important to check the substrate temperature.

To eliminate the possibility that something is wrong in the environment causing this behavior you should check your temperature range in the tank and ensure the tank is in the ideal range. If your temperature and humidity are in acceptable ranges I would not get concerned about your non conformist crabbie.

This article discusses the reasons that a hermit crab is more active at night: Why is my hermit crab inactive?

This article discusses the optimal temperature for your tank: Air Temperature versus Substrate Temperature



Your friend in a pinch,