|The goats don't seem to mind the squatters|
Research shows that hens learn the best places to nest by mimicry. In this case the later laying pullets saw those that started to lay earlier using the hay racks and decided to use them themselves even if very over crowded.
This pre-laying behaviour can last for up to a couple of hours. Then having selected the nest they settle in to the nesting material and squirm about to make a comfortable bowl shape in the hay. The problem with this site is that the eggs sometimes roll through the bars and break.
I did make a lid to keep them out but they were so frustrated I relented and let them in again. I just have to collect the eggs quickly.