In the nesting box there was just one very large egg, which I took back to the house before embarking on the daily riot known as 'dog walking'.
It was minus 9 degrees C when I went this morning to let out the hens, and give them their breakfast.
When I put the egg on the kitchen table, it rolled over showing this huge split from one end to the other (which I hadn't previously noticed); the egg was FROZEN SOLID.
Poor old chook; I do hope it wasn't frozen BEFORE it emerged.
I later fried it for the dogs!