This is actually something that happened to me last night. I have a 5 month old male Pit bull named Tobie. I adopted him 1 week ago not knowing he didn't like to be in the house by himself. A couple of days ago I left him home alone for an hour, and I forgot to shut my window. When my husband and I returned there's Tobie running around outside. It was a 6 ft. jump for him. Well last night my husband and I had to run over to my mother's house for a quick visit. This time before we left I made sure every window was shut, and every door was locked. Well we were gone for maybe a half an hour, and again we pull up, and there's Tobie running around outside. I got so scared that somebody had tried to break in and let him out. So I went to the door and it was still locked and from what I could see every window was still shut. As I was still walking around trying to figure out how he got out I went into my bedroom and I saw it, Tobie broke one of my bedroom window's to get out!! Also I must add the fact that my dog is 5 month. 60 pounds and his head is the size of a basketball, and the size of the little window he jumped out of was 8x8in.!!! Of course he was cut and bleeding , but nothing too serious. I have no idea what makes him do this.