A question of orientation.

[whistlepig]

Today was feeding day, and while watching my snake eat I became curious. So my questions aren't all that serious, just wondering if anybody had some insight. I generally try to get my snake to attack the head of the mice I feed him, but he gets so aggressive and everything happens so fast that it doesn't always work out. So a lot of time he grabs the body. Sometimes he works his way toward the head, which makes the whole process at least look like it's a lot easier, and which should, for wild snakes at least, carry a lot of advantages. But just as often he moves the other way and swallows tail end first. I've tried to figure out if there's some pattern to which way he goes (for example does he always move to his right or left? towards the end with the shortest distance between his mouth and the end of the mouse, etc), however, I've seen no hint of any pattern.

So my questions are, has anybody ever seen a pattern in their own animal? Anybody have any tricks to get the snake to eat head first? Again, just curious. Thanks.