Squirrels are bad enough, but one of our local cycling club members ran over a ground hog and nearly killed himself (the condition of the groundhog is unknown). A groundhog is a seriously large speed bump! I worry more about rabbits than squirrels. The rabbits sit there like stone until you think you will be able to pass them safely, and then the decide to run along side until it's time to dart in front of your tire. I really, really don't want to hit a rabbit.