Why is my hen manic?

[OverEasyRider]

I've got a hen that suddenly went manic. Her feathers are standing up on her head and back. She's darting to and fro squawking. Hiding, not going back in the coop with the other chickens after free ranging.She stays in hiding for days at a time and only comes out when , i let the others out. She's not leaving the back yard but, there's lot's of places to hide.

My suspicion is she has laid another nest after failing in the spring.

 

[JaeG]

Yup, she sounds broody.