This has happened several times, so thought I'd see if anyone else has noticed...and it has happened with pretty much all our roos. They will find a cozy quiet dark corner, or some other quiet place,get in it, and scratch and make little enticing noises, cuddle in the dust, and apparently try to call the hens. I think that what they are doing is showing the hens a good laying spot to lay their eggs, because it always is, or would be, a good place, that they're not using. The rooster is not dusting, because sometimes the spot they choose has no dust at all. Usually after a while one or more hens will come over and look. Then, usually the roo goes away.