She's been broody, so grouchy and depressed, and sitting in the nest box all day. Trying to hatch eggs. That will never hatch.
The cure is to take them out of the nest box and keep them outside in the sunshine till the broodiness passes. I feel sorry for them, all that maternal instinct, and no babies to be found.
Nowadays in factory farms, eggs are hatched in incubators, because you need a constant temp of body heat to hatch eggs, or a broody hen.
In the old days, the farmer would wait till a hen went broody, then put all the other fertile eggs underneath her and she would sit on them patiently for 23 hours a day for 21 days till they hatched.... It's like a phase they go thru every once in awhile.
Anyhow, this broody hen was mighty pissed at me for taking her off her nest (she even allows the other hens into the box with her to lay their eggs so she can sit on them...lol) and she was racing around the yard, just generally freaking out. And after I went inside, somehow, she jumped my 6foot fence...or somehow the gate opened...I have no idea how she escaped. Once I opened up access to the nesting boxes, she made a beeline and went back inside.
Thank god I have kind and wonderful neighbors!!!!