Ever since I got my 3 chickens, who I love, I've had rat problems. I've never had rodents before and now I can't get rid of them. I've used poison and traps. These are HUGE Norway rats that come where the food is! I'm afraid that my chickens are going to eat the poison, even though I try to put in where they don't go.
I'm sorry you are having a rat problem. This is nothing new to chicken owners, and we all handle this problem differently. There is only one reason why the rats are there, and that's food. First let's talk about food storage. The only container that I have found that will keep rats out is a galvanized metal trash bin. You can find these at your local hardware store. If you have a raccoon/opossum problem as well you can bungee the lids closed to keep them out. A large heavy rock works pretty well too!
Be careful not to spill food when you’re filling the chicken feeders because that will attract the rats right to the source. I know this is easier said than done. I know that we are all taught to keep a constant supply of food available for the chickens. If this constant supply is not kept inside a rat-proof coop at all times (and who has one of these?) then you're going to have some problems. Also, try not to feed the chickens in the yard by throwing food on the ground for them to scratch at. This is just asking for trouble when it comes to rats.
Many rats dig under coop walls and fencing to access the food. One solution for this problem is to dig a small trench (8-10 inches deep) around your coop where the food is located, and bury pieces of tin roofing material cut to size so the rats can't dig under. Hardware cloth nailed or stapled under and around your coop works well too.
One product that a friend was telling me about just this week is called Tom Cat Poison. You mix this poison with water and put it in a one quart chicken waterer. Once your chickens are safely secure in their coop at night set the Tom Cat Poison out for the rats to drink. Then remove the Tom Cat Poison in the morning before you let the chickens back out of the coop for the day. This will dramatically reduce your rat population.
If it takes just feeding your chickens once a day, and giving them just enough food to eat, and no leftovers you may have to start doing this. Norway rats have been known to jump as high as 8 feet so keep this in mind as well when storing food.
I'm sure there are many other ways to control rats around your chickens, and maybe some of our readers can tell us what's worked for them. Good luck, and thank you for your question.