I always put a crate in the pen for the puppies to sleep in. It is a hit! Unfortunately, not everyone fits in it at one time........but not to worry. We play hard now and sleep even harder. These puppies are so freakin' cute! Butter Balls! They eat puppy food 3 times a day and Geddie still stands in the pen and nurses them a couple of times a day. Yesterday she puked up her lunch for them.........oh, sure, the 12 pound puppies must be starving. As If!