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Build a Fruit Fly Trap


  • One 2-liter bottle
  • Bottle Biology Tool Kit (link to tool kit)
  • Three to five film cans
  • One plastic lid to fit inside base
  • Small amount of banana or other fruit

Step 1Remove label from 2-liter bottle.

Step 2 – Cut top of bottle 4 cm below shoulder curve. Cut the bottom off 4 cm above hip curve.

Step 3 – Poke a 3-4 mm hole in cap, just big enough for one fruit fly to pass through at a time. Invert top into cylinder.

Step 4 – Tape top securely so no flies escape. Place 2-3 slices of banana into 1 film can to start, and set in bottle base. Set the film can on a plastic lid, like that from a cottage cheese or deli container, so it doesn't tip. Once you have caught a few flies, add more film cans loaded with fruit.

National Science Foundation   Bottle Biology, an instructional materials development program, was funded by a grant from the National Science Foundation administered by the University of Wisconsin-Madison.   Wisconsin Fast Plants