Found a new problem, i heard some scratching coming from the pvc pipe in the basement! This pipe is the vent pipe from the main sewer line in the basement that goes straight up to the roof. There is no screen up there.
Do think this would be a mouse from the sewer system? Some rain lately. Or could it be a bird coming all the way down from the roof?
I notice on the 2nd floor there is a strange cut right though the venting pipe that i put some heavy tape to seal it up last year. I wonder if the previous owner used this to flush out the vent? Should i try to dump some hot water down there?