My hamster, Peamoonie, had tons of escapes before he died last July.  One time, he was in his lookout tower and he stood up on his hind legs and twisted the top off and got out.  Another time, he got out somehow, and my mom was home.  She heard something going on in my room.  So, she went upstairs and found him playing with one of our cats!  She didn't even try to hurt him!  (She is a really good mouser.)  I miss Peamoonie very much.  We sure had some great times together!