Something has moved into the ceiling inside the barn, on a piece of the sortof pressboard insulation that has fallen down a bit and left a gap. They've dropped some tell-tale moss and nest material down from above. I don't know if it's a bird or a red squirrel. I have seen a red squirrel in there, chirping at me from the rafters when I come in.
I don't mind the birds, but a squirrel in the rafters would make me crazy. They chew things to pieces, even wires. They're almost as bad as rats.