Why Does My Hermit Crab Smell Bad?

Does your hermit crab burrows and hides, some may even shed body parts?

Is your aquarium set to around 80 degrees Fahrenheit and 80% humidity?

Is your hermit crab molting?

Does your hermit crab stores water in its shell?

Are there any uneaten food left in hermit crab's enclosure?

Like most crustaceans, hermit crabs release distinct stress pheromones when stressed. This means that a hermit crab may seem smelly when you first bring it home. Hermit crabs need time to adjust to life in captivity. You will also likely find that the hermit crab burrows and hides, and may even shed some body parts. Hermit crabs can be stressed by insufficient substrate or hiding places, overstimulation through noise or light, excessive handling, unsanitary living environments, inappropriate temperature or humidity, loneliness.

Hermit crabs require a particular temperature and humidity level in an enclosure. An aquarium must always be set to around 80 degrees Fahrenheit and 80% humidity. Higher temperatures or lower humidity make a hermit crab dry out. An overheated hermit crab will start to smell musty. This is an emergency. Without rectifying this issue, the hermit crab will die. Check the temperature and use a misting spray to enhance humidity.

Molting is one of the main occasions that a hermit crab will smell. This is unavoidable, as hermit crabs need to molt to survive. Molting is the process of a hermit crab shedding its skin. The existing exoskeleton will drop off and a new, larger one will grow. This discarded exoskeleton is dead tissue. It will start to rot and smell as a result. Many owners mistake the molting process for death in hermit crabs, mainly due to this stench.

Consider how much water your hermit crab is storing in its shell. Hermit crabs retain water in case of a shortage. They also use this to drink and bathe while molting. This water can grow stagnant, though. It may need emptying next time the hermit crab changes the shell.

Hermit crabs are natural scavengers with small bodies. This means they rarely over-eat. If you leave excessive food in a hermit crab enclosure, it will be left to spoil. Naturally, this can start to smell.

Like all living things, hermit crabs need to eliminate. If you can't see a hermit crab poop anywhere, the waste is being stored in a shell. A single hermit crab poop or urine stream should not have any discernible smell. After a while, though, waste will build up. Equally, hermit crabs do not like being surrounded by their waste. Regular spot cleaning of shells and substrate is advisable.