Playing with enrichment. This old keg has a bunch of dog food and nuts in it and a hole in the side. So to get it out, they have to roll it all over the place. Of course, they also try to climb on it, hit each other with it, and run it into the wall, but thats half the fun. We give them other enrichment like fruit-sicles, honey dipped pinecones, and logs with drilled holes full of fruit.