Mosquitoes develop in large and small pools of standing waters, and not in flowing water.  Be mindful of standing water in rain barrels, ornamental ponds, troughs, dugouts, creeks or sloughs.

To prevent them from becoming mosquito development sites:

• Fit rain barrels with tight lids or screens;
• Tightly seal around any downspouts;
• Empty and clean bird baths weekly;
• Install aeration pumps on ornamental ponds and water gardens; and 
• Flush water troughs for livestock once a week.

Remember, not all standing water produces mosquitoes. Large, deeper wetlands with open water are not good habitats. Sunlit, shallow (less than 60 centimetres, or two feet deep) water with plants growing at the edge are of most concern.

If you cannot eliminate standing water around your home or yard, you can apply a biological control agent called larvicide.

The most common is Bacilus thuringiensis israelensis or Bti (Aquabac® or Vectobac®):

• The active ingredient in Bti occurs naturally and therefore has little negative effect on mammals, fish or other wildlife and will not kill other beneficial insects in the water.
• Bti will only kill mosquitoes in the larval stage (five to six millimeters long), but not adult mosquitoes.
• Bti will not prevent mosquitoes from laying their eggs in a particular water body; it can only kill larvae that are already there.
• Follow the directions as provided by the manufacturer.

You may hear of alternate methods to control mosquito larvae, including adding cooking oil or dish detergent to the water. It is unclear how effective or safe these methods are. Saskatchewan Health recommends that you eliminate standing water or make standing water more safe through the methods mentioned on this website.