A) Neither. For a long time, people believed that the common housefly, Musca domestica, performed a stunt pilot's half-barrel roll when approaching the ceiling. But in 1958, freeze-frame photography revealed that something else was going on. As Caltech insect physiologist Michael Dickinson explains, first the bug-eyed fella flies right side up at a low angle and in a direct line toward the upper deck. Just prior to impact, it instinctively extends its forelegs over its head and grabs the ceiling, using hooks or sticky pads at the ends of its legs. With the fly's front feet firmly grounded, momentum swings the lower half of its body up, like a trapeze artist. Spider-Man's got nothing on Superfly.
