Mosquitoes, a universal pest, are tricky to control since they reproduce rapidly in warm environments. It is believed mosquitoes bite people because they are attracted to the carbon dioxide humans emit. You can save money on commercial baking soda traps and replicate carbon dioxide with baking soda and vinegar to make a homemade trap for mosquitoes.
Cut off the top of the 2-liter bottle, just past the rounded part, about 4 inches from the top, using the utility knife.
Turn the top part you just cut off upside down, and set it in the bottle, lining the edges up.
Tape around the edges of the bottle to hold the two pieces together. You should have a funnel inside the bottle now.
Cover the outside of the trap with black paper, and secure it with tape. The black paper will confuse the mosquitoes once they are inside the trap.
Pour 1/4 cup baking soda and 1 cup vinegar through the funnel hole. It will begin to foam quickly. The bubbles create carbon dioxide, which attracts the mosquitoes.
Place the foaming trap where you have a heavy mosquito population. Mosquitoes will fly into the trap via the funnel hole and get caught inside. The trap is good for about one evening since the reaction between baking soda and vinegar is short lived. You can disassemble the trap, clean it and reuse it if desired.