How does a hen increase humidity?

Good question. I'll be looking for the answer too!

I find that whenever I pick them up their butts are warm as toast... so a broody hen must be really warm and steamy

 

My broody hens were always sweaty underneath the last couple of days before hatching, and all I could feel was skin, no feathers

 

I was going to suggest maybe she gets sweaty.

 

I'd say her hormones/body knows when to kick into high gear and she sets tight on the eggs....thats my high technical answer

 

I don't think chickens or any other birds have sweat glands.

There might be some water vapor loss through the skin that helps with the humidity under a brooding hen. Just speculating.

 

personally I would think that the temp is from the hen and eggs, but more hens, but the humidity is actually the egg. When you think about it they can "sweat" and in a small area they would actually increase the humidity, and the inside of a egg is very wet and the egg's pores would allow some moisture out. Heat would also help humidty rise......................also magic probably helps! hehe

just some things I think
ChiefZero

 

Also if the hen stops turning the eggs and doesn't move, all the moisture stays there. When she's turning the eggs on a regular basis, she's letting all the humidity out.