Moths use the moon as a navigation tool and bright night lights can disorient them. One experiment uses light placed outside where moths are frequently found. The phases of the moon, from new moon to full moon, should be noted and students should observe if the moon's brightness cause moths to be less attracted to the light or not. This experiment explores if a brighter moon helps orient the moths away from bright nighttime lights.
Another moth experiment with light would be to compare flames to light bulbs. A candle and a regular light bulb should be used for this experiment. Students should observe if more moths are attracted to the candle or to the light bulb. A more in-depth experiment would use a campfire and a flashlight in comparison to the the light bulb and candle. Students should observe the results over a period of a week and graph the results.
An experiment about moths' attraction to light also can be done with colored lights. Students should determine what colors of light attract moths more. Different colored light bulbs should be used for this experiment, but the wattage should be the same. Red, yellow, white and blue light bulbs will work for this experiment. Place them near each other and have the students count the number of moths that come near each colored light.
Moths feed on nectar from flowers, which reflect ultraviolet light. In the moths' search for food, many moths may go toward lights thinking they are heading toward flowers. Another experiment involves setting up lights near a variety of flowers. Use flowers that are night-blooming, such as star jasmine or tomato blooms. Test if the moths go toward the lights instead of the flowers. Students also should observe if the tomato plants are not fertilized because the moths are going toward the lights rather than the flowers.