I have not read all of the post here yet however
I am not sure I have any solutions for the chicken pen but I do have a solution if these critters are in your house or under your roof. And you can hear them
.just turn off the TV and listen.
Oh, because of our societys taboos, we do not want to admit that we may have rats and mice are in our houses. Society makes it sound like we are not clean people if we do have a rodent problem.
However, that is not true. As with most creatures like these
they get hungry and they need shelter and go where they will. The smallest unnoticeable opening is theirs for the taking.
If you want to totally poison yourself and your families and possibly causing future damage to your health...hey then go-ahead get those exterminators with their SAFE ways of getting rid of these pests. Or go ahead and use any of the other so called safe chemicals.
For ten years, I used one of those electronic gadgets you plug into the wall and it worked. It worked really well. The sound which it produced and which I could not hear and did not bother my indoor animals sure bothered the critters. They were gone the first night I used it. It is important to get one that really does what it is supposed to do. Do not waist your money on a knock off version.
Now this unit after it ten years of success is not working and I think it has died. What I use now in the house is really simple. I do not recommend this in the animal pens. I pour Clorox down all the drains in the house. I leave it for a few minutes and then follow it with a flow of cold water. Do not asphyxiate your selves.
Mice and rats take advantage of any pipe that maybe leaking and that is where they get their moisture. Even if your pipes may not leak, the flumes from the Clorox, better known as chlorine
.or as in World War One
.mustard-gas, seeps through the seams of the pipes. This will cause the beasties to evacuate immediately and they will stay away
until the next time. So every few weeks, I toss a cupful a Clorox down the drains. How easy is that? I welcome any comments.