I recently cleared out a lot of stuff from our attic and found two boards stuck together rather firmly. The top board was a piece of thin chipboard and the bottom an old board made with thin softwood planks about 6 inches wide. When I managed to prize the chipboard off, I discovered they were stuck together with a growth looking like worms or thin white rope. It was dry and a bit like expanded foam but fibrous. See the attached images for a better idea. I would be very glad if somebody can identify these growths as I don't know how to deal with them. The boards are now outside in the weather, away from the house!