The sea lamprey, with its concentric rows of sharp teeth, is part vampire and part alien invader. Would you let it suction to your arm? Reporter Dan Kraker did. Find out if he lived to tell about it.

More sport science: bats and black eyes
25:25

Sport science: softballs, baseballs, and curve balls
27:12

Is there such a thing as a blue raspberry? And why are raspberries hairy?
26:32