My mothers siamese cat did it until the day she died. You always knew Natasha had been in the bedroom as any ribbons or lace were saturated and slightly chewed. When on your lap she would fasten onto any soft dangly bit and suckle and knead. Often she got to the point where she was dribbling. We always assumed it was because she had been taken from her mother too young (5 weeks - to our eternal shame, but she was our first cat and we did not know any better then). She was 18 when she died.
