I live on a small farm/ranch and love having them around to help control rodents.
Right about now every year, the Purple Martins are in full nesting/egg laying and I'm swarmed with rat snakes.
They go right up a pole like nothing and into the gourds and live there, going from gourd to gourd until they clean the entire rack out.
After fighting with them for almost 45 years, I cut some 3" thinwall pvc drain pipe into 5' pieces, then split it so I could put it on the poles.
Before I installed them on the poles, I drilled and attached multiple strands of aluminum electric fence wire length ways with UV zipties.
I cut a slit in some 3/4" PVC 5' long to fit over the winch cables and attached two wires from top to bottom with UV zipties.
I use a small solar fence charger to heat up the wires and don't have snake problems anymore on my poles.
Wrapping bird netting around pole will stop most of them but getting them out of the netting alive is painful and stinky situation.
I went on vacation for 5 days last season and returned to this..
Me and my Purple Martins are happy with the fence charger solution and as a bonus, the coons can't climb the poles anymore!