All these namby-pamby “environmental” nostrums!
What’s wrong with arsenic and small bombs?
In my college days when I lived in a garage apartment, my landlady’s trees and roof were infested with squirrels. Loading my .22 rifle with CCI Mini-Caps did the trick and with less noise than a BB gun. Worked on pigeons too, with a city police officer standing nearby and asking if he too might take a shot (my landlady loved to call the cops and answer the door in her bathrobe but that’s another story).
Hated to have to off the little critters, but her pecan trees were spared further depredation.