When I was a kid, we used to buy fertilized eggs from a dealer, took them home and then incubated them in a home-made incubator and waited for the chicks to hatch. Slowly, one, two…and then three,..and then soon we had a small brood.
Now and then, we got some chicks which had a bare zone around the necks. Completely botak. We called them “Japanese chicks”, but to this day I don’t know why they had this feature. Could be due to some Exhibitionistic traits in their DNA ?
I think the chance of getting one was less than 1:20, so whenever one showed up in the new batch, the siblings would often fight for the right to “own” it.