Yes ... even if they can'tr get into the run they seem to be attracted to the hens. Our rat problem was compounded by the bird feeders - I did all sorts of things to stop the seed getting spilled from the feeders but there was always something there for the rats under the feeders. In the end it was a great help as a rat looking for odd bits of seed under the bird feeder was an easy shot with the air rifle from the bedroom window. Didn't solve the problem but kept it in check.My chicken shed is rat proof but they still get in the compost heap. I trap and shoot them. Rats are everywhere, all chickens do is attract them into your garden!