Watersnakes will eat more than what they find in streams. For example, eggs from waterfowl and other birds that nest near water. Since I live only a couple hundred yards from a creek, it's very probable that the watersnake (which made a nice meal for Mr. Fred who patrols that creek and the nearby field) knew my chickens were there and that they laid eggs for it to eat.
Now who am I to turn down a chance to give Fred (or Freda) an easy meal. I love hawks. I want them to stay as long as they leave my chickens alone.
Let's break it down for the watersnake...
First the good points.
-It eats rodents and probably several insects.
-It eats small nuisance species of birds like House Sparrows and European Starlings.
The bad points.
-It eats eggs.
-It freaks my chickens out.
-It smells really bad.
-It was in my shop trying to find a place to shed it's skin.
-I'm sure it carries some diseases too since it eats rodents.
And yes, you are right about the pic I posted. It was wrong. I will remove it when I finish this post. Besides, it saves me the hassle of wasting gas to relocate it.