Milk snake. Often mistaken (as I kind of did, hence didn't get too close, and was watching for cars and didn't see my finger) for a Massassauga rattlesnake, Ontario's only venomous snake. The Massassauga's range is restricted to Bruce Peninsula and southern end of Georgian Bay coast and is not very aggressive. Milk snakes are common in Ontario (though I've never seen one) and eat mice.