Yikes, about the iguana.
No snakes here, yet. Nevertheless, I keep a flock of laying hens, and a normally calm Buff Orphington will change completely if she gets broody. Shrieik and stab every day. These girls chase down and dismember mice, so it is not like its just a little tap with the beak.
I'm hoping this ongoing experience will desensitize me to some extent with the future snakes.