Why are insects attracted to light at night? Think about this for a minute. For some reason, I always thought insects are attracted to light at night for protection (is this what you may have thought one time or another too). Then I asked myself “protection from what”? Birds? Most birds don’t fly at night. Spiders? Well I know this from the past summer, if you leave your outside light off, spiders will not build webs around the light. If you leave it on, periodically or full time, spiders begin building webs. Frogs? The only time I see a tree frog positioning itself near the light is when it is on. And last OR should I say FIRST – the insects themselves…..if you leave the light off the insects are no where to be found….turn it on for an hour or so, and insects of all types begin to appear. I live along the southeastern coast where the humidity is high so when I turn my light on, the entire porch gets bombarded.
So here it goes……please note I approached this as a child of fascination. I’m not making any factual claims, trying to prove or disprove anything to anyone, or making any factual claims…..the below are my observations and conclusions.
The Mosquito Eater is receiving an energy recharge. This insect is called the “Crane Fly”. I observed it moving around the lampshade for a few minutes until positioning itself at what I prefer to call the lampshade’s event horizon. It then started waving it’s bottom leg back and forth. After 15 minutes of so of this action, the tip of it’s leg began glowing brighter and brighter (luminescence). It then placed it’s leg in a stationary position and became completely still. I was somewhat fascinated observing the tip of it’s leg glowing with naked eye so I grabbed my Nikon D-70 with 200x lens. After setting up the tripod and zooming in, I started seeing what appeared to be blues, purples, and reds fluctuating up and down the it’s leg . I ruled out the lamp illuminating various colors on it’s leg due to the fact it was completely still. This crane fly stayed on the lamp shade for about 2 hours. It would start waving it’s leg back and forth occasionally. It then flew off, made its way out of my room, the living room, and out the sliding glass door which was cracked about 3 inches. The total distance it traveled to get outside the house was over 100 feet and then made it’s way through a 3 inch opening in the sliding glass door – incredible. It returned the next night and performed the same actions. Make sure you click to fully enlarge to view the various visible wavelengths (refer to http://upload.wikimedia.org/wikipedia/commons/8/8a/Electromagnetic-Spectrum.png for reference)
I believe the glowing tip on the leg (appearing after 15 minutes) was the event area due to transfer of energy above equilibrium, In other words, releasing energy because the Crane Fly was above equilibrium thus superconducting. When energy is transferred between conduits (or mediums) we usually see and event, such as lighting, steam, etc….
Now here is the kicker…..the Crane Fly only did this on the lamp in my room that had an incandescent light bulb (which emit only around 10% of their energy as visible light and the remainder as infrared). I have two exact lamps, one with a incandescent light bulb and one with a fluorescence. I never observed this behavior on my other lamp, the same type of lamp but containing a fluorescence bulb.
Out of curiosity, I began leaving my sliding glass door open a few feet. Other Crane Flies started showing up at night. Their behavior was consistent but their proximity and action to the incandescent lamp was noticeably different than that of my 4 foot fluorescence tube light fixture (3 lights). I observed their event horizon was farther when receiving energy from the lamp with the incandescent light bulb and closer for the fluorescence tube. They would practically rest on the surface of the fluorescence tube. The majority of the time, they would stay an inch or more from the fluorescence tube. About two-thirds to three-quarters less heat is given off by fluorescent lamps compared to an equivalent incandescent lamp.
My conclusion is insects are attracted to light due to energy needed in the infrared spectrum (heat).
What is your take on this?