One of my sons has a large chicken coop and it is near his property line. On the other side there are blackberries and brush. His kids often feed the chickens and food gets left in their feeders. Now he has a rat problem. His first attempt at eradicating them was to put out poison. This killed some rats but a side effect was that his dog ate one and had to visit the vet. So no more poison. He put rattraps out all around the coop. The result was the traps tripped and no dead rats.
By now, he was becoming frustrated so he dug a hole and put a large trashcan in it. The top was level with ground and he covered this with a sheet of plywood with a hole in the center. He then put chicken feed in the bottom of the can. For the next couple of days he fed the chickens himself and kept the leftover food to a minimum. After two days, he checked his trap and found it full of rats. He then put a lid on the can and inserted a garden hose and turned it on. The result was 15 dead rats. It has been over a week and no more rats have entered the trap.
Now he and his young son have resorted to baiting the rats with chicken feed and shooting them with a pellet gun. This has proved effective; they have killed over 50 rats. But now the surviving rats are getting smarter and harder to shoot.
There are a few things to learn from this. Be careful with your chicken feed, it is a lot easier to prevent the problem than to solve it. Rats are smart and learn quickly. If anybody has any ideas sent them to us and we will let you know how they work.