My oldest Easter Egger hen, which is my top hen is mounting the group she grew up with like a rooster. She leaves the others alone. This just started about 2 weeks ago. She is grabbing the neck and then actually doing the rooster mating motion. Is this normal behavior? When I do see it happen, I pick her up off the hen she's mounting. It's only certain hens too. The first time I saw this, once she jumped off they both shook like they were fertilized. This hen has either stopped laying or slowed down drastically. I have other hens with her egg color. It's the strangest thing I've ever seen too. In the last 2.5-3 years of her life, she's never done this. I spend a great deal with my flock, so I know them pretty well down to their egg song and calls.