I have read and read on here posts that deal with these but can't find a satisfactory answer. Today I thoroughly read ml's posted article by Gail Damerow, as well. So, here's the deal: My chicken house is a 10X 24 ft metal shed that was originally a 3-sided shelter for horses ( before I built a barn then got chickens). It is set at the edge of the woods (1 side is wooded, other, not). It has a dirt floor. I have been fighting a battle with critters for 2 1/2 years. I know, we all fight critters when it comes to our peeps. I've learned so much on here about fortifying and identifying predators. Everytime I lose one, I come to the forum and read and post voraciously. I have plugged all holes 2 inches or larger to avoid weasels. I have moved everything off of the floor inside and around the outside. They free range 10 acres during the day, but it's completely fenced with field fence so I never have dogs, fox, coyotes come on the property. They get completely closed up at night and let out in the morning by me. I have shot 3 possums. I have killed two snakes in the hen house. More on that. Over the last 2 1/2 years I've found about 6 or 7 chickens - no younger than 4 months - dead in the hen house in the morning. I've never lost a young chick. The first 3 times were tophats with heads missing or torn off. The next times were simply dead bodies with no discernible injuries (I didn't, however, check their back ends to see if they were chewed up that way by a weasel - I learned about that later). I lost a frizzle cochin pullet to a hawk last year. Considering much of the 10 acres they free range is open pasture, I'm surprised there hasn't been more lost to hawks because I see them often. Just last week, I was sitting on the front porch and one swooped down right in front of me to snatch a chicken and missed when I yelled just in time. In the spring I found a young Orpington dead near the driveway and think a hawk snatched it but the dogs scared it before it could carry off the chicken. There were no marks (easily seen) on the chicken. Yes, I have 5 dogs. In nearly 3 years I've never had one catch, chase or show any interest in the chickens. Amazing, I know. I'm fortunate. So the ones that die are generally in the hen house at night when they are locked up. I say all of this to say, after learning how to eliminate other possibilities, I think the problem is rodents. As I said, my hen house floor is dirt. It's also sloped, from the woods long side to the lower pasture long side. I am more and more finding holes in the floor - every day there are several. At first I would stomp dirt in them or fill them with rocks and sticks. I considered snakes and rats. I found 2 black snakes in the house this past summer - one was curled up in a nesting box with a golf ball stuck in its mouth!. I killed both, and both were at least 4 ft long. I've been missing quite a few eggs. Now, however, after reading more, I know that they won't eat every day and certainly not several a day. And since I'm now sure it's rats, I'm sorry I killed them. Several days ago - following the advice of things I've read here - I bought snake stopper and sprinkled all around the house. I bought Tomcat rat poison, and when I find a hole, I sprinkle some down and stuff with rocks. Absolutely paranoid that my peeps can get the poison. Now, I've noticed that the entire lower side of the house has become, for lack of a better description, spongey. This leads me to believe that there is an entire network of dens, caves and tunnels under the shed where rats are thriving and breeding. I've racked my brain on how to stop this. It's impossible to get to the underneath of the shed. Because of tree roots, it's impossible to dig metal flashing or heavy fencing several inches underground around. I simply can't afford to pour concrete in that large of an area. Plus it's so sloped that I couldn't effectively do it. And I don't think the poison will effectively eliminate the problem. I think it's safe to assume at this point that there are far too many. I considered laying deer netting or something over the entire floor and securing it around the edges with tent stakes or something, but just read that rats can chew through almost anything like that. I've thought about buying some 1ft square landscaping blocks to lay around the inside but I'm not sure that will help. It know this is long, and I'm so so sorry, but please help - I'm at my wits end!