Thought this was kindda interesting... http://science.msfc.nasa.gov/headlines/y2002/22nov_balance.htm
That's interesting. In space, their brains aren't trained because they have no gravity to know which way is down. Behind the ears, inside the head, are two spaces filled with a little bit of liquid. That is where ballancing takes place. The liquid is swished around as your head moves. The nerve endings that the water passes over tells the brain which way your body is fallin, moving, ect... Your eyes are also a source of ballance, so blindfolds can help the ballancing and make it harder. Now, I don't know the ration of liquid to empty space, but cats can ballence pretty well becasuse they have a different proportion. They can ballance on the top of a fence and usualy not fall if undisturbed. We can do that sometimes, and we can also use our hands/arms with a foot to ballance. Of course, the platform for cats is much bigger to them. Just thought I'd share that with you. You might've found it interesting.