Bantams are often known for their broodiness and willingness to be good mothers. Chickens need to be instinctually driven to set for the 21 days required to hatch eggs. Not all chickens retain this natural drive. Chickens stop laying eggs when they become broody, so breeders who are focused on egg production select hens who don’t get broody for their flocks. Over time, many breeds, especially large fowl, have lost the ability to brood their own eggs. Bantam hens are often willing to hatch any eggs placed under them.
"My Nankin hens will try to hatch a rock," said Mary Anne Harley of the Nankin Club.
This quality became part of the plot in a book, Flossie and Bossie, published in 1949. “As a hazel-nut is to a walnut, a Brussels sprout to a cabbage, an Austin to a Cadillac – so is a Bantam to a regular chicken,” Eva Le Gallienne wrote in her novel about two bantam hens in a barnyard. Ms. LeGallienne drew on her observations of her own bantams to write the book. It’s now out of print, but your local library may be able to locate a copy for you.