My pesky rat friends have moved into the walls of my stone coop for the winter. I have only seen one, but I assume there are more. I really can't handle poison. The stress of worrying if my dogs (one is a 10 month old puppy) would get it or a dead rat is just too much for me to deal with. I just want to keep them out! In past years, other than a bit of food gone missing, they have never caused much of a problem. In the summer I never see them. But then yesterday I found a chicken with her neck chewed up about 15 feet from the building. I believe she died of natural causes. There were no injuries on her feet. There were no signs of a struggle. Her feathers except the ones on her neck were all intact. She was a weaker hen and we have had a very cold few weeks. What I imagine happened was that she passed away outside and then the rats came over. No other chicken had been touched. If the rats have developed a taste for a chicken dinner I am worried. I feel the need to step up my game and try to keep them OUT of the coop especially at night when the chickens are vulnerable. Of course I am assuming it was a rat and not something else? My hen died and was chewed on some time between 1:00 in the afternoon and 4:00 when I went to feed. All the other chickens were fine at 4:00. The dogs did not hit on anything strange in the run or get excited to chase a new scent.Today everyone except for a few brave chickens have stayed inside. But it's 5 degrees outside and we have snow cover. Their coop is nice and they do stay inside on really cold days on their own. I have checked on them about 8 times today!! Each time they have been relaxed and doing chicken things. Their 1/3 of an acre pasture/ run is surrounded by a 6 foot fence and then on 2 1/2 sides by an additional 5 or 6 foot fence. It's not predator proof, but it not predator friendly. A predator would have to work pretty hard to get in. Although a weasel type critter could possible get through the fences as the holes are 1" x 4". So this brings me to my question. How on earth do I plug up rat holes in a stone building in the middle of winter? One is in the wall two feet off of the ground! The problem is the difficulty of attaching anything to the stone. My DH said that we really can't just drill into solid rock! My DH plugged up all rat size looking gaps before winter with cement. But as soon as it got cold the rats chewed right through a few! I guess they were not willing to give up their winter home! Here's the hole in the side of the wall up close. And I have located two entrances on the outside of the building as well and three additional ones inside. We have been trying to plug this hole up for weeks. The floor is cement. Below shows the height off of the floor. I put a rock in the hole every night, it's in the hole in the picture below to the left of the box. Then I know if Mr. Rat has been in because he knocks the rock out! He also throws his debris out the hole-mostly hickory nut shells! I think next summer my DH will have to skim coat the whole wall....but for now, how on earth do I block up that hole!!!