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What are they?

Mosquitoes are small insects that bite and carry disease, and are generally considered a nuisance by most people.

Mosquitoes must have still or very slow-moving water to grow in. The larvae cannot develop in tall grass or shrubbery, although the adults may be found resting in these spots during the day.

The females of some mosquito species lay their eggs directly on the surface of water, in a "raft" of between 100 and 400 eggs. The eggs hatch in a day or so into larvae, which look like worms. Other species leave their eggs in a spot that will flood later, such as mud at the edge of a drying pond.

Both male and female mosquitoes feed on nectar from flowers. Male mosquitoes feed exclusively on nectar, while females must also feed on blood to produce eggs. Most mosquitoes in the wild feed on animals found in their habitat and not on people. Some species prefer birds as hosts, while others accept many animals as hosts, including humans.

Should I be concerned?

Did you know?

The entire lifecycle from egg to adult can take less than 10 days when the temperature is right.

Mosquitoes are known carriers of many diseases around the world, including malaria and West Nile virus.

How can I control mosquitoes?

Control breeding sites

Mosquitoes breed in stagnant (still) water. Remove any possible breeding sites where mosquitoes could lay eggs, even very small quantities of water.

  • Eliminate sources of standing water in your yard. Store flower pots, watering cans, boats, and wheelbarrows upside down.
  • Empty tire swings of any water and, if possible, replace them with another type of swing.
  • Cover any garbage, recycling, or composting containers to prevent water from gathering in them.
  • Drill holes in the bottom of containers that must be left outdoors uncovered.
  • Replace water in bird baths and outdoor pet dishes at least twice a week to help get rid of stagnant water.
  • Empty your rain barrel if the water is more than a week old, unless it is properly protected with a fine-screened cover.
  • Keep your swimming pool aerated, cleaned, and chlorinated, even if it is not being used.
  • Dump any water that collects on your swimming pool cover.
  • Turn over plastic wading pools when they're not being used. Change the water in your wading pool at least twice a week.
  • Keep your gutters clean.
  • Check under shrubbery and lawn coverings for hidden containers or pooling water in low spots.
  • Modify your landscape to get rid of water that collects in low areas on your property. Mosquitoes can develop in any puddle that lasts more than 7 to 10 days during warm weather.
  • Repair any leaks from outdoor water pipes, joints, or hoses. Replace washers on outdoor taps that drip.
  • Aerate your ornamental pond.


Aquatic birds, frogs, fishes, beetles, water bugs, and dragonflies eat many mosquito larvae.

Biological control

Mosquito larvae may also be controlled with the bacterium Bacillus thuringiensis var. israelensis (Bti), a naturally occurring microbe-based product. Bti causes minimal impact to the environment and other insect and animal species. Commercial Bti products are available for use in private ponds and farm dugouts where no water flows out beyond the property limits.

Other methods

In general, devices designed to trap and kill mosquitoes, or repellents other than those applied directly to the skin or clothing, have not been proven effective at reducing mosquito populations, despite killing many of them.

  • Bug zappers (electrocutor traps) placed outside have not been proven effective in reducing or eliminating mosquito populations.
  • Electronic "mosquito repellers" that emit a high frequency sound do not repel mosquitoes.
  • Claims that certain plants placed around a porch or deck will repel mosquitoes are not supported by scientifically based test results.

How can I protect myself from mosquito bites?

During mosquito season (May to September for most of Canada), limit outdoor activities as much as possible between dusk and dawn, when mosquitoes are most active. There are mosquito species that bite humans during the day, but these have not been known to carry West Nile virus.

  • Wear long pants and long sleeves, as well as shoes and socks when outdoors for long periods of time, or when mosquitoes are most active.
  • Wear loose clothes made of tightly woven materials that keep mosquitoes away from your skin.
  • Use mosquito netting when sleeping outdoors or in an unscreened structure. Also use netting to protect infants when outdoors.
  • If you choose to use an insect spray in the patio and garden area, be sure to follow label directions carefully.
  • Fix or replace old and torn screens in doors, windows, and vents. Inspect all other possible access points into your home and fix as needed.
  • If mosquitoes get into your home, you might find them resting on walls, under sinks, in closets, or in the basement. Kill them using a fly swatter.
  • Use a personal insect repellent.
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