Every once in a while i find dead field mice in the chicken water outside. They get in, realize they cant get out, and drown. Some night critter took it. They always do. I lay the dead mouse on the ground near the front gate and by sunrise its gone. i try not to encourage predators to come up near the house or animal pens so i put it up by the gate each time but man we have a lot of field mice (not everybody has mouse tight feed sheds) and they maybe need to learn to swim. (I literally keep my extra feed bags in the trunk of the car because it keeps the rodents out, keeps them from spreading disease to my chickens, and keeps this homestead from contributing to more field mice. Larger operations store more than two bags of feed at a time and cant afford this approach. They get barn cats but the coyotes always eat them. So my town has a plague of mice and a plague of grasshoppers. Its quite the place to live, but if you’re used to the area, you can make a go of it.)