How to Make a Fly Trap From an Empty Soda Bottle

fly trap made from a soda bottle

The Spruce / Michelle Becker

Project Overview
  • Total Time: 1 hr
  • Skill Level: Beginner

The tried-and-true methods of controlling houseflies indoors all have drawbacks. Flyswatters are messy and pesticides can be harmful, potentially releasing dangerous chemicals into the air.

But an easy and inconspicuous way to keep flies from buzzing around inside of your home is to set a simple trap made from an empty plastic soda bottle. Baited with some sweetened water or another attractive substance, a DIY fly trap set in a hidden area will quickly lure ordinary houseflies. Flies smell the bait and fly into the bottle to get to it (either to lay eggs or to feed). Once inside, they are easily trapped as they fly down the neck of the trap. Flies will become trapped because they can't navigate back up the narrow opening or they will be unable to fly if their wings get wet. This trap can be used indoors or outdoors.

What You'll Need

Equipment / Tools

  • Serrated knife
  • Permanent marker
  • Cutting board
  • Hole punch (optional)

Materials

  • Two-liter soda bottle
  • Bait, such as ripe fruit
  • Vinegar (optional)
  • Piece of wire to hang your trap (optional)

Instructions

materials for making a fly trap out of a soda bottle

The Spruce / Michelle Becker

Instructions

  1. Mark a Cutting Line

    Draw a line all the way around the bottle using a permanent marker, just below the tapered neck.

    drawing a cutting line on a soda bottle

    The Spruce / Michelle Becker

  2. Cut the Top off the Bottle

    Use a sharp knife with a serrated blade to cut along the line, severing the top of the bottle. Cut on a cutting board so there's no damage to your counter or table surface.

    cutting the top off of a soda bottle

    The Spruce / Michelle Becker

  3. Assemble the Fly Trap

    Remove the soda cap, then flip the top of the bottle upside down and slide it into the bottom of the bottle, like a funnel, to complete the fly trap.

    Use the Cap

    You can keep the cap on the bottle, but if you do, you will need to punch a large hole in it so the flies can get down into the trap. Keeping the cap on will further prevent the flies from finding their way out.

    inverting the top of the soda bottle into the bottom

    The Spruce / Michelle Becker

  4. Bait the Trap

    Remove the "funnel" from the bottle so you can place the bait. Choose a bait for your trap.

    Flies are attracted to nearly any decaying organic material Though it is meat and feces that flies seek out to lay eggs (the larvae, which we know as maggots, will immediately feed on those materials when they hatch from fly eggs), few people will want to use that as indoor bait. Consider these pleasant ideas for bait:

    • Slightly over-ripe fruit
    • A 50/50 water and sugar mix
    • Water mixed with honey or maple syrup for a stickier solution
    • Fruit-scented dish soap

    If you are using this trap outdoors, use a more pungent bait. To keep bees out of your indoor or outdoor trap, add a splash of vinegar to the mix.

    A Double-Duty Trap

    You can also trap wasps with this method since they are also drawn to sweets.

    baiting the fly trap with fruit

    The Spruce / Michelle Becker

  5. Make a Handle for the Fly Trap

    If you prefer a hanging trap, use a hole punch to punch two holes at the top of the bottle. Make sure they go through both layers of the trap. Then thread a piece of wire through the holes, crimp the ends, and your trap is ready to hang.

    Close the Gaps

    If you notice gaps between the edges of where the "funnel" rests in the bottom of the bottle, tape them up just in case a sly fly decides to squeeze out and escape.

    adding a handle to the fly trap

    The Spruce / Michelle Becker

Tips to Make the Fly Trap Work

You undoubtedly have noticed that there are certain times of year when flies are more prevalent. In colder climates, this is often in the spring as the sun begins to warm the walls of the home, bringing out the first flies from their winter stupor. Houseflies have a predictable lifecycle that can include many hatch cycles each season, so if you set out your trap when the first flying pests appear, you stand a good chance at minimizing fly outbreaks, since you'll be trapping most of them before they have a chance to lay eggs that fuel the next cycle.

In some environments, trapping may be an almost constant affair. In warm climates near animal pens or pastures, for example, flies may be an almost constant presence, and you'll want to keep the fly traps in place for most of the warmer months.

To maintain the trap, empty the dead flies and re-bait your trap regularly. If you decide to use meat or animal droppings (chicken litter, rabbit pellets) as bait, you'll also need to destroy any larvae that you find in your trap. Rinsing the bottle out with hot water should do the trick, or just create a fresh new trap.