The natural carrying capacity of most territories is quite small. Yes, some rats will stick around, huge colonies caused by poor chicken feeders will not be able to stick around. They will leave or starve and if they can't get to the chicken feed they won't be wildly reproducing and hungry...
"Each night, put up feeders or make it impossible for rats to access (ex: hanging feeder was moved up 5ft higher, grandpa’s feeder has a brick placed on the lid because our rats know how to open it)"
I gotta say you tried to do the right thing investing in a treadle feeder but unfortunately you...