My new roof vents. The roof had been open to the sky for quite a while. This is apparently the weakness they usually exploit to get into the attic in the first place. Note that I had asked about the active vents (the ones that spin) and been told that they leak. These are some of the better ones out there ... impervious to animals. They cost a bit more, but are well worth using instead of the small vents that hug the roof.