WHY INSECTS FLY TOWARDS LIGHT.

Auckland Star, Volume LX, Issue 230, 28 September 1929, Page 17 (Supplement)

WHY INSECTS FLY TOWARDS LIGHT.

All insects, with few exceptions, have five eyes. Two of these are the compound eyes, which are situated one on each side of the head. The three remaining eyes are of the ordinary kind and are found on top of the head. These are usually clustered closely together in the form-of a triangle. The compound eyes are for normal vision; the three simple eyes, being more light sensitive, are able to distinguish between light and darkness. This is very important, especially for the night flying insects. Under normal conditions the simple eves are illuminated equally by the sky. When an object, such as a tree, is in the way one of tho eyes receives less light and the insect turns to one si;".e until all three eyes are equally illuminated. When the light of a lamp strikes one of the sensitive eyes the insect turns its body until all three eyes receive the licrht in equal .amounts. Then it flics dfrectlv toward and into the source of illumiuatkm;. It is instinctively fascinated bv the light and cannot escape. Due' to the strange influence of the three eves the insect is lured to the light and held as if intoxicated. If an insect is arasped in the hand and thrown into the darkness, where the light does not penetrate, it will soon return, drawn irresistibly out of the shadow.