What's Down There

The last 3 weeks or so our dog Daffy has been sitting by the cold air vent. Like she is guarding it or something at first we kind of laughed at her. But as the days passed and then turned into weeks we started getting worried and thinking what is down there? So Steven got out the flash light and uncovered the vent and looked into it and nothing was there. Here we are going into the 3 week and now it's getting annoying. She is still looking into the vent,sleeping by it, standing by it. Her doggie life depends on whats in that vent :) It's crazy because we could not find anything. But she seems to think that there is something down there. Anyways I took some pictures of her and her new best friend the vent.In the second picture you will see a booked rolled up sitting on the table. I would have hit the table to scare her so she would go away and leave the vent alone then she would run and hide and 10 min. later she was back at the vent.She driving me crazy:)