 The true tree snakes, by which I mean the vine snakes and things like that, they have long tails which are prehensile. Now prehensile serves as a limb, which means they can wrap around things and anchor it. So the ideal way of moving from a branch to another distant branch is to reach out. Now you would do it by holding on to the one branch and reach out to get a secure grip on the other before you let go. Well a snake with a long prehensile tail