In Wisconsin it's deer. Seeing hit-by-car deer along the roads is common, and there are some rural areas where it's almost epidemic. If you hit one, you are suposed to report it to the local police or sheriff's dept. Considering you probably need a tow truck for your vehicle, and possibly the paramedics for yourself, you're calling them anyway, but they need to report these kills to the department of natural resources. Sometimes they have to do what's called "field euthanasia" (bullet to the brain) for the deer. If the carcase is fresh and the deer healthy, some areas will let you take the deer home for the cost of a hunting licence, so you can have it butchered and enjoy some fresh venison. Sometimes it might be butchered and donated to a local shelter or food pantry. Or some road-kills might be donated to zoos or wildlife parks. But many times along the highways, I see the carcas laying there waiting for the Highway Dept to clean it up. Worst times are dawn and dusk; visibility is poor and the deer are the most active then. This gives rise to local legends and stories, like the guy who totals his puck-up hitting a deer and the deer gets up and runs off, or the hunter who spends two weeks out in the woods and comes home empty handed only to find out his wife bagged a huge buck with the truck.