Covering the bottle with dark cloth increases the effectiveness of the trap. Mosquitoes are attracted to the mixture of brown sugar and yeast and to the carbon dioxide created when the sugar ferments. Check the trap after two weeks, clean out the dead mosquitoes and replace the fermented sugar mixture. You will need a 2-liter bottle, scissors, yeast, sugar and warm water.
- Prepare a 2-liter bottle
Cut a 2-liter plastic bottle in half, making sure the bottom half is larger than the top half. Start the cut just where the bottle becomes straight, and discard the lid.
- Mix yeast, sugar and hot water
Mix 2 cups of very warm water into 1 cup of brown sugar, and stir to dissolve the sugar. Add a small packet of baker's yeast, and stir gently to mix the ingredients together.
- Pour the mixture into the bottle
Pour a small amount of the mixture into the bottom section of the bottle, and place the top section of the bottle upside-down inside the bottom section. The lid opening of the bottle should be pointed down toward the liquid, but it should not touch the liquid. This opening allows the mosquitoes to enter.
- Wrap the bottle in black cloth
Wrap the outside of the bottle with black or dark-colored cloth, and place the trap near areas that attract mosquitoes.