Why don't animals trip and fall?

I spent a lot of time outdoors lately observing squirells, deer, birds and other animals . It amazes me how klutzly human beings are. Does a deer streaking through the woods at incredible speed ever whack his head into a low hanging branch? Does he ever trip and fall? Do squirells ever fall off pencil thin branches? Have you ever seen 2 birds collide in mid air. I mean if we lived like that...we'd be falling like flies.
I guess it's because we're not physical beings...our purpose and mission is spiritual and mental.
I think it's also because we think...athletes are always trained not to think too much. It's like when you're walking and someone comes facing you..if you don't think then everyone just naturally instinctivley knows where to go..as soon as you think..then you hesitate and ..you go right..he goes right..then you both go left..then you...well you know how it is.

I don't know..but it be would cool to see a bear get up on its hindfeet and yell OOOWWWW as it bangs its head on a shelf.