i've never actually been hunting, but i know my dad and his dad used to hunt a lot. they also used to shoot squirrels until someone got scared of the gun noises and called the police. funny thing is, the guns that were making all the noise weren't even that dangerous in long range, but the police made them switch to a quieter gun even though it was a lot more dangerous.
however, i do remember the time i accidentally ran over a mouse with my bike. it made an awful crunching sound and i felt sick all the way home.
it's funny how i feel bad about killing little things like that (except for bugs, of course) in real life, but yet i don't have any regrets when i kill someone/something in video games.
but i'm sure that if my survival depended on it, i wouldn't feel too bad about killing things like deer and such. i suppose it just depends on the situation.