I am in coastal Alabama and went for years with no issues until last year when I lost two beautiful healthy nests to snakes.
Finally discovered the Krueger trap and had a healthy fledge. It was a horrible year.
Don’t put a box too close to a tree from which a snake could drop.
Both snakes that attacked mine were 5 foot long corn,rat,or chicken snakes. They go by different names here but will take the whole brood.
