I have a mystery that I hope someone can help me with. Our house is about 5 years old, and once in a blue moon our bedroom window makes a strange noise, mostly at night. It sounds somewhat like a bee that is trapped and buzzing around. The sound is not often constant, but in spurts. Last night, however, it was constant for a while and then went to spurts. It was louder than ever too. I got up and it sounded like the noise was coming from within the window frame. I pushed and banged on the frame and it seemed to change it a little, but nothing major. We have vinyl double pane windows. Is it possible that the window, wood, or insulation could be expanding and contracting, or pressure building up for some reason. I'm puzzled.