Do i need to worry about my hermit crabs making baby crabs?

Only if you have limited space to keep them and limited food to provide them. If you've successfully put them in an environment where they will breed readily, they will keep doing this until the food runs out or you segregate the males from the females. (Put in separate areas). If you segregate too many males with too few females, the males will fight over them. If you leave too many females with a male, they will multiply until the food runs out.

If you want to limit the population, only leave one breeding pair together, and remove the rest, either back to the natural environment they came from or to other caring owners.

My daughter has hermit crabs. They fight and breed. from Nancy

Hermit crabs have never been able to breed in captivity according to all of my research.  They mate and lay their eggs in the ocean where live out their youth as plankton.  If you have an ocean in your tank you may have to worry. LOL.  Please research crabs if you have them as pets.  Some have been known to live 30 to 70 years if cared for properly.  Make sure they have enough sand to completely bury themselves in and don't bug them if they do it.  Look them up.  The pet store personnel that I have spoken to do not know how to care for hermit crabs. Lots of good info online.  Please.  The horrible suffering of hermit crabs makes me want to cry.  I have two hermit crabs that my son took in and they were originally brought home in a plastic cage that was causing them to suffocate slowly because of a lack of humidity.  We did our research and I believe our crabs are healthy although I am sure they would be happier on the beach where they were found.  We love them.

There has been one documented case where the land hermit crab laid viable eggs in captivity, and the owner put them into a marine tank. I wish I could remember the website that had the photos  :(

They all died. There is something in ocean water that we just can't duplicate in a marine aquarium the the baby crabs need.

ALL land hermit crabs in captivity are wild caught. They are picked up off a beach, or a few miles inland in the case of most Purple Pincher crabs (they migrate back to the ocean to lay their eggs) thrown in a box and shipped over here. They are not fed or watered, they go to the warehouse and then are reboxed and sent all over to petstores who really don't take the time or 'trouble' to see that their little crabby needs are met. Without humidity, these guys cannot breathe properly.

I still rescue land hermit crabs but I refuse to purchase them anymore. I do not support the methods used to collect them.

only if they are male and female.