My rabbit Sherlock poops everywhere in his pen. He will hop up on all of the surfaces and lay big round poops, sometimes in large groups as if he really is just pooping rather than marking territory. He and Simba share a pen in the kitchen, it is 8×5′ and one wall of the pen can be moved back completely during floor time. Both bunnies are altered and Sherlock doesn’t mark other parts of the house, except for the occasional poo that slips out. I sweep up his mess daily and put it in the litter boxes (there are 3 large ones in the pen because I have been trying for months to get him to spend more time pooping in them). I have tried various types of litter. Right now I am using pine stable pellets and shredded paper. One litter box has pellets, paper and a hay rack, another has pellets, paper and a handful of hay in the litter box and the last one just has pellets and hay in the box. He prefers digging through the hay to find what he wants but really shows no preference as to where he likes to do his business.

Any insight or recommendations would be helpful!