I have Googled this question to no avail. My Leo will dig his hind claws in and squeeze his hind legs together when climbing around on me. It is not just one squeeze. It is almost like a pulsating squeeze, release, squeeze, release, squeeze, release action. At first I thought he was trying to show that he was angry. Now I don't really think so since often he will follow it up with lying down and just chillin' for a while. Does anyone else's Leo do this? Does anyone know what it means? Or what he is trying to accomplish with this action? I find it interesting.