I am fairly new to chickens myself, although I have raised quail for years and also keep indoor parrots. And after just this year getting into chickens and brooding them from babies, I have learned something about the behaviors of birds that I had suspicions about all these years.
I spend a TON of time with my chickens as I also do with the quail and my parrots. And I have come to believe that when you are constantly interacting with your birds, they begin to associate you as one of them. So you come to be somewhere in the pecking order. And because you are all full of love, treats and sweetness, you can be "controlled" in the pecking orderas the lowest of meek chickens might be. I have seen this with my indoor parrots, my quail and my new babies.
I have 4 Black Australorp babies, 21 weeks old now, whom I adore. They are all girls and there is no rooster around. The highest in the pecking order, Pearl has attacked me on several occasions when I get too close to her eating, scratching in the dirt or where ever she might want to run off a lower ranking bird. And I thought Australorps were supposed to be sweet!! Well they are. But when they consider you one of them, then you are going to fall somewhere in this ranking.
The high ranking Australorp, Pearl, would bite me hard. So what I had to do was watch exactly how she controlled the rest of the others and used it on her. When she bit me, I would peck her with my finger on the top of her head, just as she does to others and this means that I am above her. This took quite a few weeks to sink into her head and occasionally she still forgets and bites me. But it does work. You have to gain control and let them know you are the leader. If you do exactly as they do to each other to the biting bird, they will get the idea.
As for my quail, some of my male roosters were the most sweetest of boys. They loved to eat out of my hand and even be handled, unlike some of the females. These ones that I got really close to, ended up attacking me now. Even some of my indoor parrots have had to be shown who is the higher ranking bird in the house.
So long story short, it does not always mean it is a rooster doing the attacking, especially if there is no rooster around. The hens can take this place of top bird and you have to assert yourself accordingly. Good luck!