Misty loves her tummy rubbed. It is a ritual when we come home from work. She is waiting for us to come home at the door and we say do you want you bellie rubbed and instantly she is on her back for the rub. If I am laying on the floor she will lay beside me bellie up. She sleeps on the couch bellie up. I think that it means they are in total trust of us and want a bit of affection.