LOL, my dad gave us kids the exact same lecture when we were growing up. We were surrounded by king, gopher, garter and rattlesnakes --lots of them. Dad wouldn't kill a rattler unless it was close to the house and woe be to anyone who killed a king or gopher snake because dad was AT WAR with gophers and other critters who tore up his garden.
We had a healthy respect for snakes -- and fear of rattlers.
Good for your Dad, he has a great mindset.