They're easy enough to kill with a stick or rock if you're inclined to kill them. I wouldn't waste my time with rat shot. I bought a box of the stuff about 25 years ago and still have most of it...
Take a pick handle with you to use as a walking stick and you're covered for just about anything unarmed that walks or crawls toward you.
Proud member of the NRA and Texas State Rifle Association. Registered and active voter.