I recently got two little hermit crabs. I also have a cat at home.

My cat sleeps in my room, but he won't stop bothering the crabs. My hermit crabs' tank is located on my dresser, which my cat can access.

How can I prevent my cat from bothering my newly acquired hermit crabs?

  • Welcome to pets.SE! Please specify your question: do you want to train your cat, or do you want to avoid that your crabs get harmed? (For the first answers will focus on the cats behavior, for the second answers will focus on how to make the tank cat-proof) Commented Nov 23, 2022 at 11:15
  • 1
    It's probably far more likely that one hermit crab will eat the other than that the cat will manage to get into the tank, get one, and kill it without being deterred or injured by the shell and claws.
    – Allison C
    Commented Nov 23, 2022 at 21:56
  • can you please give a bit of information about your setup,what have you done to make your hermit crabs and your cat safe? do you have a lid on your tank? Commented Nov 25, 2022 at 5:45
  • Hi Trond! I have a setup on my bedrooms nightstand! It has a lid but the lid has a hole so you can reach in there. We put a weight on it so the cat wouldn’t be able to get in it or move it! It seems my crabs are bothered by my cat and when they see him they hide. We just got them a bigger tank today since now i have 6 crabs, my cat has been all over the tank. Commented Nov 26, 2022 at 0:10
  • As an aside from this question, please, PLEASE ensure the food you are giving your crabs is not toxic to cats. Some varieties are, and will kill a cat! I know someone who lost a kitten to some stray hermit crab food.
    – Allison C
    Commented Dec 9, 2022 at 19:14

2 Answers 2


It's far more likely that:

  1. One of your hermit crabs will kill the other one
  2. Your hermit crab food will kill your cat

You said your cat was "bothering" the crabs without any details; I assume you are keeping the crabs in a closed tank to keep the humidity up for them, which will also protect them from the cat. They're something new in the cat's environment, and they're naturally curious creatures, so it's not unexpected that the cat would want to investigate this new thing, especially since it has small creatures moving around inside. That said, if somehow the cat were to get into the tank (improperly secured, for instance), the crabs are very well equipped to defend against the cat with their hard shells and claws.

However, on my first point, a quick Google search for "will two hermit crabs kill each other" returns thousands of results from forums, retailers, and pet care sites on hermit crab aggression, why they attack each other, and ways to prevent it. As that's not the topic of this question, I'll leave that to your own research or a future question if you need more help with it; I only mention it as the greater threat than the cat, and one that has been well documented.

My second point is, unfortunately, less well documented; I have friends who used to foster kittens, and lost one to hermit crab food poisoning, after which they discarded all the existing food and replaced it with one that was non-toxic to cats. However, searching Google for this topic only gives results on "can you give hermit crabs cat food," "what should I feed my hermit crab," and "why did my hermit crab die," nothing related to toxicity to mammals in commercially prepared foods. As this was many years ago, it's very possible that foods for hermit crabs have been reformulated to prevent toxicity in common household mammals, but I would still strongly recommend you research the ingredients in the specific foods you're using to ensure they pose no danger to your furry friend.


I had to do quite a bit of digging to find these answers.

I was unable to find information on whether or not a cat would eat a living crab, but I did find that they can eat cooked crabs and shrimp. this article says that cats will eat crab meat as a treat given to them by their owner, but I highly doubt you'll feed your pet to your other pet. Most of what I found just said that cats will eat crabs. I'm not 100% sure if it will mess with a living one though. I did find a video of a cat fighting a crab. But from what I watched; the cat showed no interest in eating the crab. So just as a precaution, I'd say you should keep the cat away from the crabs. NOTE: the video is not really a source of information, but it's as close as I could get.

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