Why do birds swoop in front of cars?

Chris Smith from the Naked Scientists takes on YOUR questions. Why do men go bald on the tops of their heads first? Do we really share 50% of our DNA with bananas? Why do birds swoop down in front of cars? Is there such a thing as tuberculosis of the spine? How is it you can tell people are looking at you out of the corner of your eye? Plus, the seagulls that are carrying antibiotic-resistant bacteria...