Rats have taken up near my duck coop, I drowned out their nest (that they setup under the concrete slab of my shed next to the coop) but there are still a good amount in the shed itself. Been baiting with baking soda and corn bread mix with decent success but I would like to have a some sort of airgun to dispatch them when I see them. Usually if I enter the coop I will see a dozen or so run up the back of the coop and out through the top, so within 10 feet of the door and there would be plenty of time to hit them as they can only fit through the opening there one at a time. My main concern is that I live in an area which is zoned Commerical-Residential, so I have neighbors. The back of my coop has 3 feet of space behind it before it reaches a fence, then on the other side of the fence is a neighbors yard with ~50 feet before the back of their house, but they also have a shed offset from my coop towards the left side (which has a window) and is also 3 feet off the fenceline (wooden picket fence).
Ideally what I am looking for is something with enough power to kill a rat (Common brown rats) but that also isn't going to blow through 3/8th inch plywood and 1/2 inch picket fence and damage my neighbor's property. I have shooting experience (grew up hunting. fishing) but am pretty ignorant about the technical verbology such as fps, mass, etc and how it would correlate to things like wood penetration. I don't think I need a rifle type airgun because as I said, it would be for when I walk up to the coop and open the door, something to pick off the slow ones and ideally without also having to pump to prime multiple times as well.