I have two girls that were faithful layers. They started laying last August and haven't stopped...until now! I changed feed 2 weeks ago. They stopped laying. So did my chickens, but only for a day or two. It has been 2 weeks since I've gotten a duck egg. I am worried. Also, on Saturday, I was in the duck pen petting my drake when my shy hen charged me. She had her head out low and stiff in front of her and she was vibrating. I went in again on Sunday and she was biting my pant legs. This is the hen that NEVER comes near me even if I am feeding peas. I have to toss peas her way so she can have treats. What could be going on with my sweet girls?