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?
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,