We live about 3 miles out a country road, and besides our place there's a 80 cow dairy farm next door. Let's see, at one time we had 38 cats and kittens! Mostly compliments of the "dumpers." Most all of them wound up living in our or the neighbor's barn, and either caught their grub out in the fields, or licked up milk here and there. We had no mice or rats, that's for sure!
The biggest problem is, they WILL duplicate. If you don't get hold of a kitten by three weeks or so, they are wild. You really can't catch or handle them. Once when I was a young boy, I helped a neighbor of ours try to lower his wild cat population. He wanted me to help him catch a half dozen kittens, about 6 weeks old, he figured. Well, he wore a large leather falconer's glove, and I held a grain sack. Those cute little "kittens" fought worse than lions. We got three of them in the sack, and had to let the rest go on being wild.
We finally got our local population under control, and keep it that way, by spaying and neutering all "pets" that people share with us. The local vets are understanding, and only charge $15-20 each. Oherwise, you'd just have to shoot them after a while, or you would literally have hundreds of wild cats running around in a very short time. May sound creul to some, but if you live out in the country and near the suburban communities who dispose of pets they don't want anymore, it can really be a problem. Taking them to the "animal shelter" isn't being kind to the pets, since they are gassed after a few weeks anyway.
BobT.
A Indiana Boy