7 Fun Facts about Hermit Crabs


Ah, hermit crabs. We’ve all had one of those summer beach vacations where we spot them in the gift shop. But there’s more than meets the eye with these tiny (and sometimes huge) crustaceans. Read on to learn some interesting facts about hermit crabs that you might’ve never known about.

1. They Molt
As hermit crabs grow, they basically shed their exoskeleton and grow a new and larger one. The molting, or shedding, occurs when the water pressure in the crab’s body builds up and splits its old skin. Something even weirder: the crab will sometimes eat its old skin in order to gain calcium, vitamins and minerals found in the composition of the skin.

2. They’re Super Social
Hermit crabs live in large groups alongside other hermit crabs – and we’re not talking only 5 or 10  other hermit crabs. Try hundreds! And ocean dwelling hermit crabs actually try to get anemones to attach to their shells in order to protect themselves. The anemones have stinging tentacles that sting predators and offer camouflage for the hermit crab.

3. They Switch Shells
As hermit crabs continue to grow, they need to find larger, more accommodating shells, just like how as we grow we need clothes that better fit us. And unlike humans, hermit crabs will fight each other if their opponent has a shell that they want. You don’t see humans fighting each other on the street for a larger pair of shoes!

4. They Can Make Themselves Shrink
While hermit crabs often fight to the death for a larger shell, they do have the uncanny ability to make themselves smaller if there is not a larger shell available to them.

5. They Have Longevity
Hermit crabs, like all pets, can live quite long if given proper care by their owners. With the right amount of TLC, some hermit crab species can even have a lifespan of up to 30 years! Maybe hermit crabs are the real pets with 9 lives instead of cats…

6. They Breed Better in the Wild
While hermit crabs can do well in captivity if they are cared for properly, they do not breed well in captivity. So hermit crab sellers have resulted in harvesting them from the wild instead of breeding them in captive environments.

7. They Have an Identity Crisis
While hermit crabs are crustaceans, they are not actually “true crabs.” They split from crabs about 200 million years ago, but are more related to squat lobsters. Fun fact: squat lobsters are not true lobsters.