Yesterday I cleaned out on of my old smelly nest boxes, which was disgusting. But I got it super clean so the hens would lay in it. I put in newspaper, than pine shavings, then nice hay. It is a wooden 3 hole nest box. I put it in my dairy goat barn which is also the home to 7 of my 50 chickens. The chickens include 2 silver laced wyandotte roos, 2 cochin hens, 1 wyandotte hen, 1 white her, and one 3 year old blue leghorn hen. I was in the barn today with my beloved goaties and I looked in the nest box. One hole was empty, the leghorn was in one, and there was something in the other but it wasn't one of my hens. So I got closer, and behold, one of my wyandotte roos! He was in a laying position, was growling like a hen, and was arranging hay in a nest! I am absoultly sure this is a roo, he crows, chases the hens, has a huge comb and waddles, and looks nothing like my wyandotte hen, plus he kicked me yesterday. Is this normal behavior? I have had chickens over 4 years and have never seen a roo in a nest box.
Maybe he was trying to get a hen to come to the box and saw you weren't one of his hens so growled? My roo tries to fit into the layer door to do his "come here ladies, lay eggs here" thing, but he only sometimes manages to squeeze in to do it from in the box.