HCA: Hermit Crab Association

Hi, unfortunately there is a roach infestation in our apartment, we just got rid of it and I found a roach with an egg sac in the crabitat. We were able to kill him and squish the egg sac, but is there any way to prevent them from getting into the crabitat? I know they're attracted to moisture and heat so its probably going to be kind of hard to keep them away I know usually they can't harm hermit crabs but since we sprayed in the house for roaches I'm worried he may have got some in the crabitat. My Mom is also worried that we'll find more with egg sacs in the crabitat and make another infestation. Is there anything that's safe for hermies that kill roaches?

No. Any chemicals that would harm roaches would also harm hermit crabs. Cockroaches can't cross Vaseline barriers. It's messy but could be used temporarily to isolate the tank. Look up live roach traps (basically a glass jar with a diving board on top and bait inside), those can be used inside the tank safely and should catch any stragglers!