When I fly myself in a Cessna, the danger is not always the critter on the airfield but overzealous animal control forgetting they are near an active runway. Was coming in on final once and told to go around as an animal control officer ran after a fox near the numbers.

As for what a hit might look like, here is a classic video clip. Not a plane but still a fast moving vehicle meeting Peter Rabbit.
http://www.youtube.com/watch?v=_mFKd9esEeU