Step-by-step explanation:
ok your problem is not a problem at all you see your dog has imprinted on the bunnies due to the fact that the dog has not seen another animal living in its home therefore it has either imprinted on the bunnies or is trying to protect his territory against them, however the fact that you said it lies by the bunnies cage is most likely imprinted on them and means no harm see dogs will lay by an another dogs cage if the dog inside the cage is locked in there its perfect normal for this to happen because dogs are like people they get lonely to the dog is probably trying to give the bunnies some company so they are not lonely
hope this helps