Indeed. The Marans came from France. The person who breeds them is an old school chicken keeper with one of those rambling farm houses.
Their chickens go in and out of their house and have afaik for the last 80 years. Not sure of the provenance of the Bantams.
It's very easy to forget that the keep chicken in coops and runs method isn't how much of the rest of the world keep chickens.
Should you go to Asia (the home of the wild jungle fowl) you will see lots of chickens wandering around the villages and going in and out of peoples houses.
If you visit one of the cultural/heritage museums here there are lots of pictures of farm houses with chickens in the kitchen and they're not dead chickens.

Chickens have been sharing accommodation with humans and other animals since their domestication.
It's the humans that don't understand this, not the chickens. It takes a bit of cultural adjustment and common sense to differentiate between wild fowl and domestic fowl.
Not being stupid creatures they will go where there is maximum safety and here it's my house.
maybe the picture below suits your perception of 'natural' environment better.
This is the same tribe that are in the earlier picture.
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