It's getting really cold out and we have a terrible rat problem that we can't stop. We have a few banty chickens and to keep them warm in the winter, my husband built a wooden house/run for them. It's not tall enough for us to walk in. We have hardware cloth on some of the sides for ventilation and near the door, he built a wooden platform with wood on the sides. The rest of the area bottom is dirt. I would say it was around November when we started noticing a tunnel leading under the door/platform and when my husband shook the house, a rat came running out. We have tried multiple times to catch this rat while he was under the house, but now, he's gotten smart and only comes at night after we have gone to bed. I'm not sure where he goes during the day. Now, he's made a tunnel all the way through under the platform and is coming in and eating the chicken food every night and drinking their water. We tried putting cinder blocks and bricks around the door and along the sides of the run, but he just digs a deeper hole in front and under the bricks and still gets in. We've tried pouring a whole bag of rocks under the platform and he dug all the rocks out and still got under. We've tried a large live trap, which he won't go in and then we recently purchased a small live trap for mice. It looked like he went in it one time, but it appears that he was able to get out, so I think it may have been too small. He hasn't gone in it since and I'm afraid if we purchase a larger one, he won't go in it either and we will have wasted money. This is one determined, smart rat. I know we can use a snap trap, but we also have goats that sometimes walk around the area, and I don't want them getting their feet snapped. Today when I went to feed the chickens, I noticed several tunnels coming into the coop from all sides. We've got to get rid of this thing. He is eating a ton of food, costing us money. I'm not even sure how much the chickens are able to eat because almost every day, the feeder is empty, when they used to take at least three to four days to eat that much before Mr. Rat came along. I also know that mice/rats carry all kinds of diseases that could make chickens sick or kill them. Does anyone have any other ideas of how to get rid of this rat? I don't want to put poison around my chickens, but I'm afraid that while he gets a free meal every night, and since it looks like he's already aware of what those metal things are, he won't be willing to go into anything else. Please help. I'm all out of ideas.