Black snakes are not poisonous but they do have fangs. They kill by crushing their prey to death. They kill birds that are too big for them to eat. I have had birds killed by them and I tried to rescue a duckling that was being crushed and could not get the snake to let go in time to save it...
A broody hen who attempts to defend her eggs or babies instead of leaving the nest is likely to be killed by a snake even when it is too small to eat her. My daughter had a broody hen killed by a snake.
A black snake killed a month old duckling on me this year. It was wrapped around her and would not let go till I grabbed it with pliers and swung it. I dislike snakes but so far have not killed one on purpose but that may change. There are 2 kinds of snakes around here black and copperheads. I...