Moths are well-known for being attracted to nighttime light sources, such as candles, lanterns and landscaping lights. However, moths aren't the only insects attracted to light. Flies, praying mantids and many other creatures are also phototaxic, meaning they are drawn by the light. Different insects are drawn by different wavelengths depending on the types of light they are most sensitive to. Homeowners with colored patio lights may see different insects than those with bright white lighting.
Moths are among the most obvious insects that come out at night when lights are on. According to field ecologist and naturalist Dr. John V. Richardson, Jr., these insects are more sensitive to white and UV light than to red or yellow light and may think that human light sources are the moon. Artificial light sources may prevent moths from navigating correctly or confuse them into believing that a sexually receptive moth is nearby. These confused insects fly around and even into artificial light sources.
Some types of flies are also attracted to man-made light sources. According to the University of Florida, bottle flies and blow flies are both strongly attracted to light in their adult form. Since they are often active inside the house, homeowners may find these flies buzzing around or even inside light fixtures. Other flies attracted to light include eye gnats, tiny black flies which buzz around lighted windows. These insects may hover unpleasantly around the face and eyes, since they are attracted to moisture.
Several predatory insects are attracted to artificial light, possibly to prey on other insects like flies and moths. Assassin bugs and praying mantids may be seen in pools of light, waiting for or consuming their prey. Adults are often found on or around porch lights in late summer. These creatures are also attracted to UV wavelengths and may appear near black lights. These predatory insects are beneficial since they consume pest insects, and should be removed rather than killed if they become a nuisance.