I suspect the type of plastic used on yours and mine are very similar if not identical, and there's no added insulation here. I have many times found eggs resting directly on the plastic in the middle of a nest of shavings, with no
obvious ill effect on hatching. Hatching rates have varied but the causes have not been identified, except infertility; maybe that is one, so I'll keep it in mind henceforth.
Oddly almost the same thing happened here in on day 5; I found Venka's egg on the floor in the middle of the coop, and Ystrad had added another to the clutch (so the number of eggs was the same) and must have gone in to lay when Janeka was off. Venka's either was carried out under a wing, or it might have rolled out the front edge and Ystrad laying was just coincidence; but I've since put a bit of cardboard across the front lower edge to raise it a bit to prevent further such losses.
It certainly is for Janeka who's a chunky welsumer

And she's on an upturned turf, so is raised nearer the roof and her tail feathers pay the price. She doesn't seem to mind though. She'll moult soon enough.
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I was expecting the same with outdoor tomatoes and basically the same weather here, yet I ate my first red tom yesterday and another is orange on the plant that was bought started and went in first. So sunshine and warmth are not essential it appears. Those I grew from seed are about the same stage as yours, and I've got my fingers crossed for them. They're a Czech variety called Stupice that is supposed to be good for outdoor conditions. The bought one is Gardener's delight.



Adorable