Rattle Snakes

This morning I was driving up the drive out of the Ranch and near the mailbox found a rattlesnake coiled in the road. I was in a hurry so I pulled up to the snake slowly in my car and ran it over. It made a popping noise similar to that of a small balloon popping, it was kind of gross. I left my car on top of it and got out of the car to check it out. It was decent sized, so I took out my pocket knife at cut off the buttons. It only had about 9 buttons. I hate rattle snakes and this unfortunate snake was in a highly traveled area. I jog past the route every couple of days and my wife takes the baby for walks to the mailbox quite often. It was about 3/4 miles away from the house. I just didn't want to take the chance of someone getting bit, or my dog getting bit, or a cow getting bit for that matter. It was kind of odd and I noticed this but I actually felt bad about killing the snake. I don't know why. I mean with my hunting situation I kill a lot of animals. In fact to give you a number, in the past year, I have killed 3 deer, 1 elk, 1 antelope, 20 geese, 30-40 ducks, a couple of pheasants, 200+ prairie dogs, 10 rabbits, 4 raccoons, 7 skunks and a partridge in a pear tree.(there is probably more but I think you get the picture) I don't waste animals, I eat every thing I kill except the prairie dogs , coons, skunks and rabbits and don't remember feeling bad about killing any of them. But snakes I feel bad about. I just can't figure it out. I don't kill any other snakes besides rattlesnakes, but it is weird. maybe I am weird, well there is no maybe about it. I don't think that I have ever killed a snake and not felt bad about it. Maybe I am not supposed to kill snakes, I can't figure it out. I was never taught not to kill snakes, I hate having them around, I am scared of snakes, but I feel bad about killing them. Maybe I am just screwed up.
Any analysis would be appreciated.

Here is a picture I took at the construction site that I am over seeing. It's kind of a cool view.