Every now and then during a home inspection, we come across some eyebrow raising items, in this case birds in the attic.  These guys were hard at work, likely attempting to build a nest under the very edge of the roof vent which seemed like a good idea at the time.  Unfortunately, this roof vent was missing a screen to keep birds and animals out, so their efforts to build a nest up at the roof around the vent resulted in all the nest material dropping into the attic space. Check out the full article on Birds in the Attic.