What are the sexes of the bunnies? They're acting a little wild right now, and there may be some behavior that wouldn't be so good if they were mixed-sex.
Mama Bonnie from Cabin Creek Acres says:
The bunnies are too little to know, for sure, what they are.
As of now, I think there are three males and one female.
They will be off to their "forever" homes long before they realize it.  Keeping them together for several weeks helps them socialize, making them lovable, fun pets for their new owners.  When bunnies are grown up, it is hard to get them to share a cage, even if you have them spayed or neutered at the vets.  It takes time and patience, so for now, we'll let them enjoy playing together.