I tried traps--no joy...
. I tried a bate that is vitamin D based and causes a toxic overload and is not poisonous if the dead rats are eaten....They did not eat it.
. I bought a rat zapper and it works but too slowly....Only get one every couple of days. I finally picked up Tomcat liquid bait. It is a second generation Anti-coagulant and rats cannot resist drinking it! It is listed as a Medium dangerous poison and is slightly toxic if the rat is eaten. It can be treated with vitamin K so is not as bad as the worst one--that one has not treatment. I put out a little cup in a place that cats can't get to it and they were drinking a cup a day of it....
. I do have to make sure the rats do not die where the chickens can get them. I also take the feed in at night and have all the feed in covered trash cans. I should be able to keep them under control with the Rat Zapper now.