ha yeah I do have one I keep outside the pen just cause I don't feel like going through all the crap to go in and change his lolMain reason I quit using them is my pens are all screwed down with no doors "no chance of escaping" so I stick to the cups. Then every now and then I scoop em them all up in a couple of buckets and scrub them out. Within about 30 seconds they get em dirty again lol