Fruit Fly Trap – Simple, Effective & Easy to Print

🍎 Fruit Fly Trap – Simple, Effective & Easy to Print

A simple 3D-printed solution for one of the most annoying kitchen problems: fruit flies.

The Fruit Fly Trap is a compact reusable funnel designed to fit over a glass or small container containing an attractive bait. Its conical geometry guides fruit flies toward the center opening, allowing them to enter the container while making the exit much less intuitive.

🔬 Compact & Functional Design

The model measures approximately 75 × 75 × 53.6 mm, making it compact enough to use next to fruit bowls, kitchen counters, sinks, bins or other areas where fruit flies tend to appear.

At the center of the funnel is a 3.5 mm diameter entrance hole. This small opening was chosen to provide an accessible passage for fruit flies and other small flying insects while keeping the entrance deliberately narrow.

The radial slots around the cone help the scent of the bait spread into the surrounding air, while the funnel geometry directs insects toward the central entrance.

🍎 What should I put inside?

For a simple indoor setup, place the trap over a glass or container and add:

Recommended bait

• Apple cider vinegar

• 1 small drop of unscented dish soap

Apple cider vinegar provides the fermented smell that attracts fruit flies, while the dish soap reduces the surface tension of the liquid, making it more difficult for insects that reach the bait to escape.

For an alternative fermented bait, try water + sugar + baker's yeast.

You can also experiment with a small piece of very ripe or fermenting fruit together with the liquid bait to increase the fruity aroma.

⚠ Important: the liquid should remain below the tip of the funnel. Do not fill the glass up to the entrance hole.

🪤 How it works

Scent → Funnel → 3.5 mm entrance → Trap

The bait releases a strong fermented/fruity aroma. The slots allow the smell to diffuse around the trap, attracting fruit flies toward the funnel. Once they find the central opening, they enter the container and encounter the bait below.

No insecticide is required: the design works using geometry + an attractive bait.

🖨 Easy to 3D Print

The Fruit Fly Trap was designed as a simple and accessible print.

My prototype was printed in Bambu Lab White PLA, which is a great choice for normal indoor use and gives the trap a clean appearance that fits naturally into a kitchen.

Indoor use: PLA recommended
Outdoor use: ASA recommended

For outdoor applications, Bambu Lab ASA is preferable because of its higher resistance to heat, weathering and UV exposure compared with standard PLA.

♻ Reusable by Design

Instead of throwing away an entire commercial trap, simply:

1. Remove the printed funnel.

2. Empty and clean the glass.

3. Add fresh bait.

4. Put the funnel back in place.

One print, one ordinary glass, fresh bait — and the trap is ready to work again.

Simple to print. Simple to use. Reusable. No electronics. No insecticides.

Sometimes the best solution is simply good geometry. 🪰