Broody or freaked?

[dreamdoc]

I added (gradually) two hens to my flock and all was fine for a month. Last week one of my older gals had a bloodied comb. One of the newer Americana's has been aggressive towards her all of a sudden. For awhile she hid under a bush and was the last to enter the coop. They appear to being settling down but she is lately spending most of the day in the nest. The banty rooster is continually chasing her to mount and she get's totally freaked. Yesterday she got aggressive, briefly with another hen but it was short lived. Can't tell if this is pecking order behavior, who the aggressor is, who the victim is, etc. Is there a chance she is broody ? Is this why a calm hen is being attacked by one hen and stalked by the banty rooster? I thought she was staying in the nest for protection but now I'm not sure? Advice or opinions? Thanks for any feedback.