I have a 4 year old cat, Nellie, and a 3 month old kitten, Fred. Fred is a very active kitten and Nellie is a laid back sorta cat. When they play Nellie mouths Fred all over. Im sure its just play, cuz Nellie could hurt him if he wanted. Is this normal. Eventually Fred gives up, lays on his back and begs for mercy. Nellie is indoors recovering from an injury and Fred is an outdoor cat soon to be barn cat. Im just wondering if this is a normal behavior when cats play. Ive had two cats before, one older and one younger and never seen this behavior. Any advice?