Squirrels with Death Wishes

Heading to work this morning I had a squirrel throw itself under my wheels.  I did not have time to stop before it was under my car and I heard that tell-tale thump.  Looking back in my rear-view mirror I could see it flailing around on the highway and just felt sick to my stomach.  I don't know why I take this so much to heart, but I do, and it just ruined the rest of my day.