While driving on the highway to Montreal, I saw a carcass in the middle of the road which I barely avoided. I did hear a slight thump as a wheel went over part of it. Monday I see a whole bunch of porcupine needles stuck on a tire. Although the animal was dead, the mechanism for releasing the quills on contact must have been triggered automatically. The car that struck it initially must have had many of the longer needles stuck into one of its tire.