I have 5 laying hens, and they have been really busy lately. Last Friday, they gave me 5 eggs. Saturday, I got 5 more. Sunday, I had 6. ??? I know exactly which hen laid which egg, and in this case, Rusty (an ISA Brown) laid the extra egg. And she laid another yesterday (Monday). From everything I've read, this isn't supposed to be possible, but the only other possibility is that one of my juvenile layers (14 weeks) laid her first egg, but that would seem even more miraculous. So, do hens occasionally lay 2 eggs in one day, sort of like a double yolker?
* They can. It doesn't really take all that long for an egg to form in a hen, surprisingly. So, in summer, they have enough time (daylight) to sometimes do 2 in a day.
I'm glad you asked this! I posted the same question a few days ago and no one answered it. I have a 19 week old Leghorn who laid her first two eggs just hours apart. She has been laying one egg a day since then (the last two days). I guess you and I got some "freebies"!