My 17 mo old neutered male has been air humping at times. He will be walking across the floor and will start humping for no reason. At other times he will be eating and start doing it..he looks as surprised as I do and it seems to be uncontrollable

. When I touch his back or speak to him, he will stop. I went back and read all the prior posts containing 'air humping' but don't see anything similar to his actions. What do you guys think, and thanks in advance for your thoughts.