Fred's Hens :
If you have 10 hens? give or take? and you're serious about solving this, then you might consider committing a morning to "charting" the hens. I take my coffee and a clipboard and head out to the coop early in the morning. Note, the boxes are empty, OK, we're good to go. One by one they head into the boxes. When they leave, I assign a description of the egg and the hen who laid it. After an hour, they've mostly all laid. I can even separate them into a divided pen, layers into one, not yet laid, into the other.
Narrows it down. Eventually, I have charted them all and know who does what and when.
Another method is lipstick butts. Different shades of lipstick on the bums of each hen. The eggs get streaked with different color at lay. A chart is then constructed. Different ways to chart your hens. Gotta do something.
Different shades . . . that's one way to get easter eggers
I have just started to get eggs and I don't know if one was just lazy or what but one laid an egg right next to the feeder. So far though 5/6 made it to the nest.
I may try the lipstick trick if I find any more outside of the nest. Thanks for the idea.