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Does keeping the light on keep mosquitoes away?

Does keeping the light on keep mosquitoes away?

Mosquitoes can be a nuisance when trying to enjoy the outdoors. Their bites can leave itchy and irritating welts. This leads many people to ponder what steps they can take to avoid mosquito bites when spending time outside at night. One common question is whether keeping lights on deters mosquitoes or if darkness makes no difference to these relentless pests.

How Mosquitoes Use Vision to Find Hosts

Mosquitoes use a variety of different senses to locate hosts to bite. Smell and heat sensory organs are likely their primary means of detecting potential sources of blood meals. However, vision also plays an important role in their host seeking behavior.

Mosquitoes are attracted to specific wavelengths of light. They use their eyes to identify hosts by detecting motion and dark colors contrasted against lighter backgrounds. Mosquitoes have special photoreceptors in their eyes that are sensitive to ultraviolet, visible, and infrared light.

These photoreceptors allow mosquitoes to see their prey vividly even in low light conditions. In fact, some species of mosquitoes are most active during twilight periods around dusk and dawn when there is a mixture of light and darkness. Their eyes are adept at identifying hosts during these low light times.

Keep in mind that while vision is used by mosquitoes when foraging, their sense of smell is still the dominant factor in finding and targeting hosts. They can detect carbon dioxide, lactic acid, ammonia, and other compounds emitted from the host up to 50 meters away or more.

Do Artificial Lights Deter Mosquitoes?

Artificial lighting around homes and outdoor living spaces is sometimes recommended as a way to repel mosquitoes. The theory behind this is that the light will disrupt the mosquitoes’ vision and ability to identify hosts. However, studies on the effectiveness of artificial lighting at deterring mosquitoes shows mixed results.

Research has found that certain wavelengths of light can inhibit mosquito activity. Specific narrow bands of short-wavelength light in the violet-blue color spectrum have been shown to deter some mosquito species.

Conversely, some longer wavelength lights, such as those in the red-orange end of the spectrum, were found to attract higher numbers of mosquitoes in scientific trials. Warm incandescent bulbs seem to draw in more mosquitoes compared to neutral or cool LED lighting.

Unfortunately, broad spectrum white light that contains a full visible range of colors neither deters nor attracts mosquitoes effectively. The most common outdoor lights used around homes and yards do not appear to impact mosquito activity significantly in either direction.

Do Natural Light Conditions Affect Mosquitoes?

Besides artificial lighting, some research has investigated whether natural light conditions make a difference in mosquito activity and biting behavior.

Photosensitivity impacts mosquito species differently. Some types are more sensitive to light and others are more attuned to following scent trails to find hosts. In general, though, most mosquitoes become more active in low light around dawn and dusk.

Mosquitoes typically rest in shaded areas during the day when sunlight is abundant. At night, they are better able to spot potential prey against darker conditions. Their vision is adapted to function well in low light when contrasts are more noticeable.

Moonlight, starlight, and sky glow can provide enough illumination for mosquitoes to identify hosts and navigate towards targets at night. Artificial lighting from buildings, streetlights, and lamps similarly allows these vampiric pests to see at night.

Some research indicates that a full moon supports increased mosquito activity levels. More moonlight translates into improved vision and hunting success rates for mosquitoes.

So paradoxically, keeping outdoor lights off at night during a full moon may potentially reduce mosquito biting activity compared to leaving the lights on. More studies are still needed though to confirm if darkness truly deters mosquitoes when abundant ambient moonlight or artificial light is present.

Tips for Preventing Mosquito Bites at Night

While keeping lights on at night does not conclusively repel mosquitoes, there are other more effective steps you can take to avoid their bothersome bites:

  • Use insect repellent – DEET, picaridin, and other repellents applied to exposed skin deter mosquitoes from landing and biting.
  • Wear loose, long sleeve shirts and long pants – Covering up limits access to your skin.
  • Eliminate standing water sources – Drain or treat places where mosquitoes breed like bird baths, old tires, and clogged gutters.
  • Run fans – Mosquitoes have trouble flying against currents from fans.
  • Use citronella candles or torches – The scent covers up attractive smells to mosquitoes.
  • Treat yards with residual insecticide – Products containing permethrin or deltamethrin kill mosquitoes on contact.

Along with taking preventative measures, be sure to keep screens in good repair around windows and doors. Mosquito netting over patios, decks, and pergolas provides an added layer of protection when spending evenings outside.

The Bottom Line

Evidence that artificial lighting deters or repels mosquitoes is limited. Typical broad spectrum white lights do not seem to impact them noticeably. Mosquitoes naturally take advantage of low light conditions to hunt successfully at night.

While counterintuitive, trying to replicate daylight conditions with bright lighting may not thwart these adaptable pests. Vision is only one of the sensory inputs mosquitoes rely on to find hosts to bite.

A better strategy is employing multiple tactics like wearing repellent, removing breeding grounds, and using fans, candles, and torches. Take steps to make your yard and outdoor living spaces as inhospitable to mosquitoes as possible.

With some vigilance, you can still enjoy the evening and nighttime hours outdoors with less annoyance from persistent mosquitoes trying to steal your fun and blood!

Frequently Asked Questions

Do mosquitoes prefer to bite at night?

Many mosquito species are most active at dawn and dusk when there are lower light levels. They will readily bite both day and night. Some types actually prefer to hunt during the day. Mosquitoes are opportunistic and will bite whenever hosts are available.

Do citronella candles really keep mosquitoes away?

Citronella candles provide some protection against mosquitoes. The citronella oil fragrance helps mask scents that attract mosquitoes to hosts. Citronella candles are more effective at close distances of about 3-6 feet. Any breeze dissipates the protective fragrance quickly.

Should you sleep with lights on to avoid mosquito bites?

There is no definitive evidence that sleeping with lights on deters mosquitoes or prevents bites. Mosquito netting treated with insecticide around beds provides the best barrier against bites while sleeping. Eliminating mosquito entry points into bedrooms is also key.

Do mosquitoes bite more when it’s hot or cold out?

Mosquitoes tend to be most active during warmer months of the year when temperatures range from 80-95°F. Cooler temperatures inhibit their activity levels and survival. However, in some regions warmer weather breeds more mosquitoes, leading to higher populations and more bites.

Are mosquitoes attracted to light colors or dark colors?

Mosquitoes use vision to identify hosts by detecting contrasts and movement. Dark colors stand out more against light backgrounds, especially in low light conditions. Light colors reflect more wavelengths that may deter some mosquitoes. But no color reliably repels them.


Mosquitoes are adaptable and use multiple senses, including vision, to locate and bite hosts. But keeping outdoor lights on at night does not dramatically deter these pests. They are able to utilize low light conditions and moonlight to find targets to feed on.

A better mosquito bite prevention strategy includes barriers like netting, repellents, protective clothing, and eliminating breeding sites. Avoiding being outside at peak activity times for mosquitoes also helps reduce exposure to bites.

With vigilance and common sense precautions, you can still enjoy the outdoors in the evening without letting pesky mosquitoes spoil your fun!

Lighting Condition Impact on Mosquito Activity
Bright white light No significant effect
Incandescent light May attract some mosquitoes
UV and blue light May deter some mosquitoes
Red and orange light May attract some mosquitoes
Darkness Enables mosquito vision and activity
Full moonlight May support increased mosquito activity