Turn Yeast into a Mosquito Killing Army!

Mosquitoes are drawn to CO2.  Yeast create CO2.  So, use yeast to draw mosquitoes into a trap.

I heard about this tip somewhere and thought I’d share it with you.  It cleverly uses yeast’s carbon-dioxide bi-product to trick mosquitoes into going into a bottle.  Since mosquitoes are also drawn to heat, you can paint the bottle black to make it extra temping.  This is a very natural and eco-friendly pest control.  You can just use some old bread yeast, although some spent beer-brewing trub (pronounced TROOBE) will work awesomely too.

Mosquitos Trapped in a 2-Liter Bottle

Items needed

  • 1 2-liter soda bottle
  • scissers
  • 1 cup of water
  • 1/4 cup of sugar (white or brown)
  • 1 teaspoon of yeast


  1. Cut the plastic bottle in half.
  2. Mix sugar with hot tap water. When cool, pour in the bottom half of the bottle.
  3. Add the yeast when the water is cool. No need to mix. Yeast eat sugar, and then creates carbon dioxide which attracts mosquitoes.
  4. Place the funnel part, upside down, into the other half of the bottle.  You can tape them if you want.
  5. (optional) Paint the bottle, or wrap it with something black, leaving the top uncovered.  The black will absorb more heat during the day.  Both the yeast and mosquitoes like it warm.
  6. Place the trap along the edges of your yard.

Maintenance (Every Few Weeks)

Add some more cooled sugar water every 2 weeks so the yeast has something to eat.  If there are a lot of dead mosquitoes, and or the liquid looks especially nasty, spray it out and start over.

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