We saw several of these on the wall along the driveway of the house we are moving into. Samson got one down for us. It was really interesting. It was like a heavy brown paper on the outside and then there was a thick layer similar to insulation. It was hard to tear into but when he did we saw the nest of dozens of caterpillars which will eventually turn into butterflies of some sort. Samson did not want to touch the caterpillars because he said they will make you very itchy. He also said that some people like to eat them. Apparently they feed on the leaves of a tree that is on the other side of the driveway and then they crawled down and across the driveway and up the wall where they made their cocoon.