As of now, all of my snakes and all of my mice are in the same room. All of my snakes are agressive feeders, but aren't bothered by this and some are inches from the rodents.The biggest thing with me is to keep the mice very clean. They will"stink up" the place in no time. There's about 140 adult snakes and about the same number of adult mice at any given time in the same "room." I still must buy frozen to accomodate though. Hoping to build a new mouse house this winter to give me more room and add some more racks of each.