I will maake you a bet that someones cute Easter bunnies got big and oops cages got left open. You are probley seeing the results of the bunnies being loose and breeding, If they are hopping around then they are old enough not to need mom as they will keep them close by. I would get a haveaheart trap and get them to a bunny rescue or to your local shelter. If you can find some one (try a 4-H club your local dept of agrucultrue ) who can tell you the sexes so you can seperate them and keep them from breeding . Rabbit will start at 10-12 weeks (just after weaning)