HCA: Hermit Crab Association

Since you've come to the emergency forum, we know you want a fast answer to your question. In order for us to figure out the problem as quickly as possible, we ask that you answer the following questions as best you can. Some of them may seem odd, but they're all designed to give us the information we need to give you a good solution for your problem. The things in the [ brackets ] are there to make this post easier to read once submitted. Thanks!


1. What kind of substrate is used in your tank and how deep is it?
EcoEarth/Sand 50-50, was ~8”, just set a new enclosure up and now closer to 10”.

2. Do you have gauges in the tank to measure temperature and humidity? If so, where are they located and what temperature and humidity do they usually read?
Usually about 80•F, 75-80% humidity


3. Is a heat source used in the tank? If so, what?
UTH adhered to the side of the enclosure above the substrate level

4. What types of water are available (fresh or salt) and how is the water treated (what brands of dechlorinator or salt mix and what ratio is used to mix it)?
Salt and Fresh pools treated with Prime and OceanSafe, I think is what it’s called.

5. What kinds of food do you feed and how often is it replaced?
Variety of fresh and dry. Dry food is replaced as needed, usually every 2-3 days. Fresh is pulled after 24 hours.

6. How long have you had the crab and what species is it, if known?
2 PPs, 6mo in care

7. Has your crab molted, and how long ago did it happen?
???

8. What type of housing are the crabs kept in, what size is it and what kind of lid is on the housing?
Previously in 10g (they were very small when I got them). New enclosure is 40g.

9. How many crabs are in the tank and about how large are they?
2 - both now in 3/4” opening shells

10. How many extra shells are usually kept in the tank, if any?
Usually about 10, now since setting up new tank only 4 since these 4 were the only ones not already in the tank

11. Have there been any fumes or chemicals near the crabitat recently?
No

12. How often do you clean the tank and how?
I don’t really. Sometimes I’ll wipe the sides down with prime water when I change the food/water dishes out

13. Are sponges used in the water dish? If so, how are they cleaned?
No

14. Has anything new been added to your crabitat recently?
Previous enclosure no, new enclosure is exclusively new.

15. Is there any other information you would like to share that might be helpful (anything that is regularly part of your crab care, playtime, bathing, etc.)?


16. Please describe the emergency situation in detail.

I recently started to notice a couple ants in the crabitat. I stopped offering fresh foods and only offered dry. I admit I wasn’t monitoring the enclosure nearly as good as I should have been, I haven’t seen any evidence of ants in the house and assumed the fresh food was drawing them in. Tonight I was cleaning the tank/changing food and water out and realized there were some more ants. After moving their things around I stirred up an entire colony. They built a nest and have apparently been living there. I panicked and set up the enclosure I have been waiting to move them to anyway since they are getting bigger now. I set it up with 10” EE/playsand and cleaned a few of the things from their old tank with very hot prime water (in my panic I dropped my lighter for the stove into a bin of water, so couldn’t boil water tonight). I put the crabs in a cup and waited about 30-60 mins and no ants came off them so I let them go into the new enclosure. I put almost all new things in there because after digging around in the old tank everything was just covered in ants. After setting the new tank up as best I could for the night and getting the crabs settled in I decided to look up ways to help prevent reinfestation and read that nothing from the previous tank should be put in a new enclosure until boiled thoroughly and that the crabs should be quarantined just in case. I already messed up. What do I do? I’m so stressed and upset that I let this happen. I pulled all items that were previously in the old tank. What else can I do?

I read suggestions on a previous post about Vaseline/double sided tape and will be doing that tomorrow. The old tank is just sitting on the counter surrounded by a barrier of ant killer, so they can’t really leave the enclosure without dying. I’m still trying to figure out what to do with that disaster. I’m hoping since the scent trails go to that tank the ants will all try to go there and die.

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Personally, I think what you did is enough. You are correct that a entire colony is possibly dangerous to crabs, and that the tank needed torn down. Basically the two crabs are 'isolated' together in a new tank - I don't see how further isolating them would be beneficial. I would do what you said, and put vaseline or double sided tape around the new tank, to prevent any from getting in. And just keep a close eye that no ants came over on anything from the old tank.

If it is only the ant colony isolated in the tank and you have a big enough freezer you could put them in there. It is often considered the most humane way of putting down colonies among ant keepers but like I said you need one that is big enough. A quicker way is pouring boiling water on them but clean up probably wouldn't be easy. You could starve them out but that is a long process and not an easy one. If you can identify the specie and it is native to your area, make sure it is, you can release the colony into the wild. If you do release them I do want you to make sure they are native. There are other methods but these are just the ones I can think of off the top of my head. Remember as well that the queen is the only egg layer so when the queen dies the colony dies with it.
To prevent them from getting out Vaseline/double-sided tape are good. Baby powder mixed with rubbing alcohol is also a good barrier when dried but you need a good amount for it to last long.
I am not sure where you live but nuptial flight season is also coming up in the northern hemisphere where male ants and unfertilized queens fly out and mate to found new colonies, the males die afterward so don't worry about them. This sounds like a big and established colony though so I doubt it could have gotten in because of that. Ants also eat just about anything so I don't think the change from fresh to dry did much.