Do you have a rooster? Sometimes, in the absence of a rooster a dominant hen will try to fill the void and act very much like one. There is also a fairly rare condition where a hens working ovary quits and the non working ovary can develop into testes like organs and the hen will take on rooster traits. They don't lay eggs (so it says) when that happens. I've had hens do the first, I've never had one with the second issue. You may just have a very aggressive, dominant hen, who is trying to be the rooster for the flock. Or you just have a dominant, aggressive hen. I had one that was just a monster like that when I went for a period without a rooster. Once a rooster was back in the flock she settled down and went back to just being a hen. Hen or roo, I personally would not keep one that flogged or spurred me. Last roo that spurred me was not around very long. You can trim the spurs and blunt them. But it still hurts if they nail you.