Learn why bugs are so attracted to light.
Ever wonder why your porch light is covered at night with insects and moths?
According to Mike McLean of the Metropolitan Mosquito Control District in a CBS report,
“It’s kind of complicated, but bugs need a little bit of light in order to navigate.”
Just as bees use the sun to navigate, some insects and moths use the moon’s light on a constant angle in order to help them maintain a steady and straight flight course.
This is called phototaxis: “the ability of organisms to move directionally in response to a light source.”
Some insects are attracted to light and some, like cockroaches and earthworms, are repelled by it.
Since artificial light is found in abundance and brighter than the moon, the insects end up trying to navigate by your porch light and become really confused. The light is stronger in one eye than the other and that in effect causes one wing to beat faster which brings about the constant flying around in circles.
Instinctually, the bug wants to keep the light on one side of its body in order to navigate, but the roundness of the artificial light prevents that from happening.
Some scientists think that light pollution is leading to a decline in certain insects. For example, the population of fireflies has dropped off considerably in certain parts of the world.
Some theorize that light from homes and street lamps interferes with the firefly’s flash patterns which in turn affects their mating rituals.