The other day one of my professors asked why moths were attracted to light. Someone thought it might be because they thought it was the moon. But even granting that moths might not be bright enough to tell a porch light and a celestial body apart, why should they be interested in the moon? Please, Cecil, this may be worth extra credit to me. –Shannon, Montreal
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For many years it was thought the moon did have something to do with the attraction of moths to light. The so-called light-compass theory held that moths used the moon as a navigational beacon. By keeping it at a constant angle to their direction of travel, they were supposedly able to fly in a straight line. The trouble came when they made their sightings from a close-up light source like a candle flame. Instead of heading in a straight line, they flew around the flame in an ever-narrowing spiral until finally, phhhht, moth flambe.
A number of other theories have also been discredited. Some claim that, to the moth, bright lights mean open space and open space means safety. But moths are nocturnal, and the night sky has no light sources anywhere near as bright as a porch light. Besides, why should the moth feel compelled to fly around the light in circles? Others argue that moths associate light with warmth. Yet ultraviolet lamps, which are much cooler than incandescent bulbs, attract more moths.
You were kind enough to enlighten me concerning pheromones and aphrodisiacs, so I now turn to you again. Can I get AIDS by engaging in sex acts with another woman? Please hurry, my life may depend on your answer. –Robin Razzano, Glendale, California
