Do Crabs Have Shell Fights Under Substrate?

Where we discuss the behavior of our hermit crabs, as in fights, pecking orders, shell swaps, etc. Please post all naked-crab posts in the Emergency forum.
Post Reply

Topic author
Posts: 8
Joined: Sat Oct 13, 2018 5:31 pm
Location: Florida

Do Crabs Have Shell Fights Under Substrate?

Post by SR245 » Tue Jan 29, 2019 5:16 pm

Hi guys, to cover pre requisites I have a set of small PP and 2 E's in a 29 gal. 7 in Sub, and I keep the tank around 85-87deg and humidity just under 90.

The E's like to dig a lot, but they haven't been aggressive towards the PPs in the time I have had them, and they've got a selection of around 16 shells I keep in an upper level shell shop, so selection shouldn't be an issue. D's and O's. I alternate the diet between, proteins, and dried fruits. Mainly egg when we have them, and shrimp. The fruit is tropical.

Lately some fellows have gone down, the E's are fairly regular and come out during the night consistently to eat, but the 2 of the PPs are doing the "lets pretend to be dead for a month" thing and molting, or setting up to molt. I can hear them on the glass occasionally.

Question is if they encounter each other beneath the sub, what is the likelihood of a fight breaking out underground?

I've gone through one molt cycle already without anyone digging someone else up and eating them, if anyone's asking.

User avatar

Posts: 1355
Joined: Tue Aug 08, 2017 9:56 pm
Location: Coal Region in Pennsylvania

Re: Do Crabs Have Shell Fights Under Substrate?

Post by Motörcrab » Tue Jan 29, 2019 6:14 pm

I believe a good bit of their time is pre and post molt. For pre-molt they will try and find a quiet spot where they aren't disturbed for what they seem is a safe amount of time. If they are found by another crab during this time they will probably try and move to another spot and repeat the process. After the decide they are safe they will molt.

After they shed their exo they will be soft and not able to easily move without damage. This is the danger time for them. They leave off an odor that smells good to crabs too. If the molting crab is accidentally disturbed at this point they are at the mercy of the crab who found them.

User avatar

Posts: 1531
Joined: Sun Sep 05, 2010 3:54 pm
Location: Manitoba, Canada

Re: Do Crabs Have Shell Fights Under Substrate?

Post by curlysister » Wed Jan 30, 2019 12:09 am

The only time I had a problem with one of my crabs coming across the other when she was down molting was when I didn't have enough substrate. Many people recommend more substrate for E's, like at least 10 inches.
How large are your crabs, and how many are in your tank? Here is the HCA recommendations for tank/ crab size and numbers. ... 26&t=92541
Also, be sure you are giving your crabs a source of calcium. They need protein and calcium every day. There's good info about nutrition in the Food section.
"If there are no dogs in Heaven, then when I die I want to go where they went." -Will Rogers

Post Reply