Looks to be a dermestid beetle larva (Coleopter: Dermestidae) and probably a young instar (larval moult) of a Dermestes spp. The larvae of these beetles feed on a wide range of organic materials including stored pet foods (dog/cat biscuits), abandoned foodstuffs in cupboards and even accumulated kitchen spillages. They are not harmful to you rabbits but are a household pest if present in good numbers. See if you can find a potential source and check that you do not have and infestation that you are not aware of at the back of a cupboard.
But remember, one Demestes larvae does not constitute and infestation - no need to call in the pest controllers yet.