My hens do this if they don't like something. I have one crazy hen (where's my stew pot?) who runs at me and gets really aggressive if I happen to be walking toward her head on. Keep in mind that my movements are always slow and I will go around a chicken rather than shoo her out of the way. Respect usually goes a long way toward happiness on both sides. However, this one will come at me and growl. Of course I just pick her up and pet her all over and there she is, growling and growling and growling. My daughter was afraid to touch her so I stroked miss henney's wattles while the petting was going on and controlled the head. Still growling.