The hope is that as the fly walks across the surface, its little body charges up, allowing poisonous spores to stick to its body like metal shavings to a magnet. If this happens, then soon enough, the fly will walk no more.
Why aren't airliners equipped with parachutes? That question is answered on this Moment of Science.
Contrary to popular belief, you don’t have to have fruit in your house to have fruit flies. All you need is fermenting organic matter that remains wet or moist. Most likely, that’s going to mean drains–sinks, showers, etc. In particular, fruit flies tend to breed in slow-moving or seldom-used drains in which a layer of slime has built up.
The relationships between plants and insects are often intricate and complex. One such relationship is that between the yucca plant and the yucca moth.
A recent study of bugs and bug zappers has shown that while there’s enough electrical energy here to zap the fly, there’s not enough to harm any germs the fly might be carrying. What do you think happens to all those germs?