We have just bought a 12 week old female Border Collie and we are trying to train her to sit. Unfortunately she must have overdosed on belly rubs at the breeder's place because she constantly drops to the ground and rolls over hoping you will scratch her belly. If you walk around the garden she races in front of you and drops and rolls. I've lost count of the number of times I've accidentally tripped over her. You try to teach her to sit and force her into position, but as soon as you let go .... drop and roll over with legs in the air. I have told the rest of the family not to rub her belly if she rolls over. I have tried stern "No's" and also ignoring her and walking away, but she is still obsessed with belly rubs.
Does anyone have any suggestions how we can get her to 'unlearn' this behaviour?