Not your fault DebAnneDigi, so much flat out useless advice is given and people dealing with rats will try anything to get rid of them. The traps and rat poison only gets a few young and dumb rodents, the breeding age rodents are too wise. The plaster of paris is an old wives tale, tested in that University of Nebraska study, the rats had some sore Iranian holes and little else. Stomach acid isn't water and the constant churning breaks up anything that is trying to harden.
But dealing with rats is very easy. Two methods that do work every single time.
First method, build a Fort Knox tight coop. Gonna cost a lot of money but it works.
Second method, bulk feed in metal drums with tight lids, clean up the pathways so the rodents have to travel in the open, predators will get some of them and make it harder for them to travel, and the last step is buying a rodent proof treadle feeder. Most of them are not rodent proof, you will NOT find a single one on
Amazon that is rodent proof and reading their negative reviews proves that. Get off
Amazon, only Chinese junk that has huge markups can be sold on
Amazon.
What a treadle feeder needs to be rodent proof is a narrow and distant treadle, not a huge wide, close in treadle step. Think roost pole size, far away to prevent swarming and overwhelming the feeder. Second thing, an inward swinging door so it is safer and so it can trap the rodents IF you have a swarm of dozens and dozens of rats. I've only seen that on commercial flocks. They will trap themselves and they will smother themselves and the remaining rats will not touch that feeder again. And on that inward swinging door it HAS to have heavy springs or the rats can just push the door open. The springs should be adjustable.