I have 26 cameras around my property including 4 in the attic. They range in brand, model, and price. I'm using Blue Iris as my NDVR and it's doing the motion detection for each stream. Since nothing moves in the attic, it's set to most sensitive settings available.
26 cameras!!! That is some bandwidth.
Thinking about adding a camera or 2 to my Ubiquity Dream Machine Pro. Never thought to add one to the attic, but it would capture any critters.