Each day, some signal tells my hens to lay eggs. Only they can hear it. But when it goes off, they all rush to the SAME nest, line up, and make a huge racket waiting for their turn to lay their egg for the day. Nothing is more important or more urgent in those five minutes.
Now I know why:
Apparently, they all fear that if they don’t get that sucker laid, the next day will be a double sized, double egg day.
It’s very cool that you have them trained to lay in the same nest. Easy to collect all the eggs!
Ow, my cloaca!
They’re probably not even trained, actually. Hens just have a natural attraction to any spot that another hen has deemed a good place to lay eggs and will preferentially lay there. That’s what “nest eggs” are for–you leave a couple eggs (or something that looks somewhat like an egg) in the nest so the hens will lay there instead of seeking out new and potentially inaccessible places.
Of course, our hens aren’t nearly so lady-like as the OP’s and scorn this waiting in line stuff. If multiple birds need to lay at the same time, they just pile up in the nest on top of each other. It’s a pretty funny thing to watch.
My mom’s chickens fairly routinely lay eggs as big as four ounces, but she’s never had a Matryoshka egg from them. I don’t think she even gets double-yolkers.