Our 17 week old Rouen - jury is still out on male/female.....is doing something new. The 3 mallards, whom we have established as hens, do not seem to be doing this. When I enter the run through the gate, Soap, the Rouen, will come up to me with his head sort of bowed down, not stretched out, grunting. It is not an aggressive or antagonistic rush like the ducks will do to the chickens if they cross the line of what the ducks consider good behaviour. It is a very deliberate, slow walk up to me. If I crouch down, Soap will come right up to me and almost press his/her forehead against mine, all the while making this grunting noise. After, if I stand up or sit down, he just does his regular shnerbaling at me with his bill along with the 3 girls, pulling at laces, sticking heads in pockets and up sleeves, if I am sitting. I've noticed this behaviour in Soap for about 2 weeks now and it is consistent. Soap does not seem to do that to my son, who is Mom to them. Any ideas? **EDITED** To say it is NOT head bobbing. His/her head remains still.