They're complex and awesome creatures. I had one, named Alfredo, who lived for years, because I did the research.

Nearly all hermit crabs have been kidnapped from the beach, and that made me feel so guilty... I didn't know when I got him from a mall.

They can't just go in a tiny aquarium, or they'll get depressed, malnourished, and die.

They need heat rocks to remember basking in the sun; they love snacks (Alfredo adored cheez-its covered in peanut butter); they have gills, so their shells must have water in them, or they'll stop breathing; they love exercising... you can get the hermit crab version of a hamster wheel and they will play on it all day. They're also really social. They want friends, places to hide, places to dig, to roam and explore, and if they do, they'll live a long life.

My sister is the hermit crab expert in my family, I mostly only have second-hand knowledge through her

But for starters it is really damn hard to breed hermit crabs in captivity, so basically every one you've ever seen in the pet trade is probably wild-caught.

They also have really specific habitat needs, high humidity, warm temperatures, access to fresh and salt water, deep substrate that they can dig and burrow in, vertical areas they can climb on, I think you should ideally have like 10 gallons of space per crab, and basically no hermit crab kit out there actually meets these needs.

And while a lot of people think of them as sort of throwaway pets that will only live a few months, with proper care they can actually live years, even decades.

https://slate.com/technology/2025/08/hermit-crab-lifespan-beach-pet-cage-breeding.html