When mosquitoes are buzzing around the room, patience quickly runs out. This classic DIY trap exploits the insects’ craving for CO₂ and sugar. It can be built in under 5 minutes using materials you’re guaranteed to have in your trash (or kitchen).

The Turbo Yeast Trap

This trap mimics human respiration. Since mosquitoes are attracted to the carbon dioxide (CO₂) we exhale, we use fermenting yeast to trap them.

What you will need:

1 empty plastic bottle (1.5 or 2 liters)
200 ml warm water (not boiling!)
50 g brown sugar (white sugar works too)
1 packet of dry yeast (or half a cube of fresh yeast)
Some tape and a dark piece of paper (or a sock)
Instructions in 3 steps

Prepare the bottle: Cut off the top third of the plastic bottle with a utility knife or scissors.

Mix the attractant: Pour the warm water into the bottom part of the bottle and dissolve the sugar in it. When the mixture has cooled slightly (lukewarm), sprinkle the yeast over it. Important: Do not stir! The yeast should work slowly.

Activate the trap: Place the top part of the bottle upside down (like a funnel) into the bottom part. Secure the rim with tape so that no CO₂ escapes from the sides, but only through the opening.

Why this works:

The yeast “eats” the sugar and continuously produces CO₂ in the process. The mosquitoes fly through the funnel into the bottle, but can’t find their way back out and end up in the liquid.

The secret to success:

Mosquitoes love dark places. Wrap the bottle in black paper or a dark sock. The combination of CO₂ and darkness is irresistible to these pests.

Quick alternative for fruit flies: If you’re not talking about mosquitoes, but rather the small, annoying fruit flies, the vinegar and dish soap mix will help:

Fill a glass with apple cider vinegar (attractant).

Add a splash of water.

Very important: A drop of dish soap. The dish soap breaks the surface tension of the water. The fly tries to land, but immediately sinks and drowns.

Are you dealing with the classic “bloodsuckers” in the bedroom, or are you more bothered by the tiny flies in the kitchen?