Actually this hen went broody before and hatched five of seven this summer. A roo and four henlets 18 weeks old yesterday. Either is was a coincidence she went broody or it was because I left the eggs to collect in the nest, and when she had seven she decided to sit on them. I had just gotten that pair of OE and they were in a separate pen.
I don't eat the eggs, or I didn't then...I just feed them to my dogs. So when she made a nest recently and laid two eggs in it I decided to see if the same thing would happen. I'm pretty sure they were all her eggs as I don't think my only other hen is laying yet...she was 25 weeks old yesterday. They are all in one coop now, and of course it is a lot colder now...12 degrees today.
On this nest she sat on them for two days...then I moved her. It was the moving her that disturbed her broodieness...and she was moved twice. She also sat on them overnight and they were warm when I let her out of the second cage. She just didn't go back on them. They didn't get cool, they got COLD. I'm sure they died.
This was an experiment and I didn't care about hatching the eggs...if they weren't hatched, they would have just been fed to the dogs. I don't want to start incubating. I have plans for next year to breed, but the hens are going to have to do it.
I've partially completed what I call segregation pens...six of them...and next spring I'll move like kind chickens and roosters into them with outside small cooplets/large (and dry) nesting boxes. I've had two batches hatch successfully that way. I'll collect the eggs for a couple weeks (as the roosters and hens would have been mixed together up to that point) then see if any will go broody for me. Those will be purebred chickens...or as purebred as chickens can be.
And...how can you tell if a hen is stressed? No, really. She eats, she poops, she maintains her place in the flock, and she acts perfectly normal. I house five roosters together with six hens and they don't even fight.