Why not a thread on this topic. We talk endlessly on here about peoples dogs in our yard. I think the Op was smart to come here and get a different perspective. Before I had chickens my neighbor (I use to call her Ellie Mae) had geese that free ranged including in my yard. Once I got some goose poop in the carpet of my car and house and finally had enough. I told her about it, but she did not do anything right away. I think once she realized I was sending my dogs out after them is when she finally took action. It was that or the geese get killed. The OP needs no real reason to not wanting those hens in their yard. "Their yard" should be enough reason. What I don't get is the folks that want to know why. The only reason why I ever needed was they are NOT MINE! I had the same issue with Ellie Mae and her rabbits. She thought it would be cool to release hald a dozen rabbits to "help out the population". I've never know rabbits to be in short supply and need that kind of help. Once I figured out what was eating up the wifes flower gardens they were siliently eliminated. YUM!