Gives a bad name to vermin, who are useful to coyotes and other predators. I prefer a simpler term..."cowards".
Nope. The word is "vermin," as in cockroaches and lice. With vermin, you simply kill them without mercy, and without qualms.
I think the way we and the Japanese, or the Russians and Germans fought in WWII, gives us an example of how a "vermin" classification differs from your standard "enemy" one.