Rats are common when you live on the coast, but I haven't helped things by having a feeder out for the birds. Now I am going to have to deal with this. :(
Oh no! I hate rats. They are tempted by the droppings around the feeders especially if you use tiny mixed seed. I now only use sunflower hearts and find the birds take the whole seed and there is less mess on the floor. Maybe my two terriers (rat catchers) help to keep them away? Maybe they come at night when I don’t see them! Good luck!