We’ve all watched it happen, and chances are we never really thought about it that much. Bugs—particularly moths—are attracted to light, but why? It’s the principle that many bug traps and zappers are built on, but no one knows just why it works. There are a couple of different theories about why moths are attracted to light, but there’s not even one that stands out as a front-runner. In fact, there are pretty convincing arguments against all of them.One theory suggests that only man-made, artificial lights attract bugs. Presumably, there’s something different about artificial light that interferes with the bugs’ ability to navigate, but we don’t even know whether bugs are using light as a navigational aid. It’s also been suggested that moths may be confusing the frequencies of artificial lights with pheromones given off by willing mates, but there’s nothing to really support that theory, either.
Researchers have found that it’s a pretty bizarre behavior, specifically because it seems to cross species but also works against the survival of those species. In spite of the kamikaze behavior that could be expected to discourage the practice—or at least kill off the part of the population that does it—it’s still a major behavior pattern.