Why are insects attracted to light?

Have you ever wondered why that moth that incidentally got into your house last night keeps buzzing around the ceiling light or why lit mosquito traps work so well? 

The researchers say they discovered three key things when studying insects’ attraction to light. First, if the insects flew above it, they would turn upside down and plummet as they tried to fly upside down. Secondly, after they pass under a light, they tend to start lopping around, climbing at a steep angle before they stall and eventually fall.

Finally, the researchers found that the insects fly at right angles to the light, circling them or “orbiting” the light instead of flying straight at it. While it might appear that the insects are flying directly at the light, it’s believed that the body’s control systems are being interfered with somehow, causing them to experience these effects.

The belief is that the insects are experiencing what is called the “dorsal light response” due to how they try to keep the light to their back anytime they approach it. This reflex is also seen in some fish and is essentially a way for animals to determine which way is up and keep their bodies upright. This experience often works without issue. However, at dusk and dawn, insects can experience problems with it.