She's got 11 kids under there at this time.  Notice the little feet sticking out the front and the head poking out the back.  The kids go from one hen to the other, so they keep the average between them at about 8.

I think it's having enough space and private places.  10 birds in a 10 X12 greenhouse with places to hide.  They lay communally but once the hens get hormonal they chase everybody away.  Currently 2 mom's are sharing 20 kids.

How'd you get them to brood by themselves? I've had to do it myself thus far.

Oh my gosh, this is the cutest thing I've seen in a while. Birdy super mom :)

Lumpy Mom 11 under