Have you ever wondered why various winged insects (such as moths or nocturnal butterflies) tend to behave as if they are attracted to artificial light sources? Isn't it harmful, and often suicidal, mode of behavior? After all, what is in it for them? Why waste time and energy on clumsy bumbling about a lamp or a candle, visible to all predators, in the company of other equally hapless creatures, and risk an untimely death by burning your delicate wings with a characteristic "Zap!"?

It turns out that this behavioral anomaly is largely well understood by biologists (although there is still scientific debate about details going on). It turns out that flying insects have built-in navigational systems based on the notion of light sources (e.g., stars and the moon) being far, far away -- an infinity away, as far as each insect is concerned. If such an insect needs to fly in a certain direction in the face of adversities such as winds and obstacles, all it needs to do is to strive to maintain a constant angle to one of such convenient light sources. This has been an invaluable and reliable navigational technique for more than 99.99% of the insects' evolutionary history, as the notion of a light source that is not, for all practical intents and purposes, an infinity away simply did not exist.

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