I have four chickens, two BR that are now almost 2 yrs old and two beautiful Buff Rocks that are 29 weeks. One of the buff Rocks, Rose has started to bite me and try to hold on! They would both give a quick peck from time to time when I am in the run but I put that down to curiosity. Rose is now biting in an aggressive manner and raising her neck feathers when she does. Why is she doing this and how do I put a stop to it without scaring her?