Scarce Parus sp. provokes cleaning frenzy

Despite the fact that I've been both stingy and erratic when topping up the feeder in our garden so far this winter a Marsh/Willow Tit was good enough to pay regular visits this morning. I like to watch from our hall window but am ashamed to say that it was so grubby I couldn't see through clearly enough to clinch an id. Cleaned the window, a statistically rarer event than the potential sighting, but still no good. Needed to be outside to hear the bird. But what to do to pass the time? Decided to clean the inside of the car. Another very rarely undertaken chore. And after ten minutes the target bird alighted in a tree above me and called. Marsh Tit.