OK - absolute weirdest thing ever. A few days I ago I swore I heard a male singing in the backyard. Sure enough he was on the wire above where they nested this summer (I had one succesful brood that fledged 5). Then this morning I saw a female on top of the box. Still thought nothing of it. Looked in the box...half built nest!!!! WHAT is going on! It's October - in Western PA!!?