Originally posted by SuperDave:

Wow... I'm just now learning that there are Chickens available in Valheim now? Never seen one in the Mistlands.

You have to buy at least two eggs from the trader after killing Yagluth. They must be kept warm in range of a fire, but make sure they can't access the fire because they will find a way to go stand in it, briefly.

And yeah I think you have to be nearby for them to lay eggs. They are tricky and will drop eggs through walls occasionally, and hatch through walls as you found out. Any chicken coup should have a second fence around it to catch the odd stray. I built a barn in my base with a short half wall surrounding it. I advise centering the doors instead of putting them in the corner because those chickens will pile up in the corner. Or if you are good at round buildings that might be a solution.