So far our dog, Toast, has had a lot of fun with this. It's different from the treat balls he plays with and I think the weight is a positive factor that drives interest. We call it his "weeble" like those little dolls that used to go with the playskool houses when we were kids. I often take it to work when he goes with me. It isn't as challenging as, say, a level 2 or 3 puzzle, but he can use it unsupervised and it takes longer to empty.