We had a pair of Cardinals trying to peck their way into our dining room for about 5 days--I moved the plants away from the windows, hung towels up so they didn't see their reflections, put a fake snake on the deck chair outside the window and hung plastic grocery bags on the chairs to they would flap about. They FINALLY left--think she wanted to nest inside! We lost a large pine this fall and think they usually nested there.
think it's the reflection thing--windows with screens were not appealing.
We've been keeping an eye on the barn swallows too--some summers they want to build their mud nests on our house--what a mess! And they are just as diligent--took my DH sitting on the porch most of a day with a hose to discourage them last time.