Depends on the dog. Some may wreck your home and get into things they shouldn't and may urinate or little hockey pucks around the house because they are generally ticked off you've left them. Most dogs sleep a lot, look out the window, gnaw on a chew bone, chase their tail or if you have two dogs they may play with each other. Mostly, they're just waiting for you to come home. Oh my, what a loyal friend dogs really are!