All our chickens are over a month old. We have segregated them into a large meat flock and a small laying flock (hand-picked gentle hens). I have two obvious roosters in the meat flock and so I tried out each one with the laying flock. Bachelor #1 is an Orpington and he got into it with the Orpington hens. He kept ducking under them and upsetting them. Is this normal? I put him back in the meat flock and tried out Bachelor #2, a Barred Rock. This rooster also dove underneath he hens, but not as often. I think we'll go with Bachelor #2 because he's nicer to the hens but what the heck is with the rooster going under the hens?
I would think since they are so young the roosters think your hens are mommas and may want cuddled, warmth! Just a guess