Bunnies will never be stopped with a treadle feeder, they weigh more than a hen and have a longer body. Squirrels can be stopped but you have to double up on the springs and put the tension directly on the door. We have a retrofit kit for our older feeders if anyone has one of our feeders...
Curios as to why the treadle feeder failed on something as easy to stop as sparrows.
What type of treadle feeder and how did it fail? Might learn something new from the answer.
Thanks