Right so what did the camera actually pick up? Footage or just audio? Because the reason I'm asking is that attics are genuinely interesting spaces for this kind of thing - the geometry of the roof space can create standing wave acoustics that make sounds seem to come from multiple directions at once, which rules out straightforward animal intrusion pretty quickly if the sound is shifting around.
I've done a fair bit of equipment work in confined spaces like that up at Rendlesham forest area and the acoustic properties mess with your head. That said, what you're describing with the weeks of recurring activity does suggest something with a pattern, and patterns are what matter. Random noise is just noise. Repeated cycles at similar times or under similar conditions is worth documenting properly.
Was it rhythmic? Any sense of it responding to movement or sound from below? That last bit is the detail people always forget to mention and its usually the most telling thing.
