Reusable Ant Trap with Sliding Lid

The Ant Trap V3!

This design is for the home to be placed near the baseboards along the path the ants are walking. It has been optimized to be most effective for ants and their behaviors with:

• 2 small holes on each side

  • Worker ants walk along baseboards like a 2 lane highway, having 2 openings at each end ensures they do not have to veer far off the path to go through the trap

• Dark/small enclosed area

  • The trap has been designed to have a floor to roof height of <0.20" which is optimal to mimic their colonies and be a place that is comfortable and inviting for them

Printing:

Scale: This design it is fully scalable within your slicer of choice. I personally use 125% but you can experiment to find the best size for you.

Material: I recommend PETG, as the trap is designed to be usable and PETG is the better material for toughness and durability, and to be washed. This trap can really be printed with any material though.

Layer height: A lower layer height is recommended <0.12mm, although you can still get a functional print on higher scale with larger layer heights. 

Strength: I would recommend a high wall count, I used 8 walls with 40% adaptive cubic, if you would like the trap to last and be reusable. If you would like to use it more as a disposable trap, 2-3 walls with 15% infill is fine. (Note: For the liquid base, 8 walls or a slight flow bump of 101–102% ensures the reservoir well is completely watertight with zero weeping).

Support: None; designed to be printed with no support, brim, raft, etc.

Orientation: Bottom bait chambering facing upwards and lid is bidirectional either side flat on bed:

General: Ideally print this by object instead of layer by layer to prevent errors with the small lips & overhangs.

Using the Trap:

1). Select a slow-acting ant poison/bait:

Choose a high-quality bait/poison, slow-acting formulas are essential because worker ants must ingest and carry the bait back to share with the queen and brood rather than dying instantly inside the trap.:

A). Viscous gel bait (such as Combat Max, Advion, or Maxforce) and print the bottom (BottomV3).

B). Liquid-based bait (such as sugar-borax solutions): Print the base marked for liquids (BottomV3_Liquid) , which incorporates a recessed reservoir well to prevent low-viscosity solutions from leaking out of the entry holes.

2). Print and prepare the parts:

Print the base and sliding lid: be sure to pick the correct bottom file according to which bait you are using from step 1.

Preferably this should be printed in PETG for moisture resistance, durability, and safe cleaning. If managing a wide perimeter or multiple rooms, print several units. Quickly inspect the side grooves and clean off any minor stringing or bed artifacts so the lid slides smoothly. Other materials that would be equal or better would be: Nylon, ASA, PPS, PPA, PC, etc. (but these are overkill for this application but will absolutely work). PLA would also be fine if you intend on using them as a disposable trap.

3). Load the bait chamber:

Gel Base (BottomV3): Dispense 2–3 pea-sized dabs of gel onto the center floor of the base. Keep the bait centered and away from the sliding channels and the side entry ports to prevent gel from smearing the tracks or leaking out.

Liquid Base (BottomV3_Liquid): Use a dropper or syringe to fill the center recessed reservoir without overflowing past the rim. Tip: Place a small pinch of a cotton ball or cosmetic sponge in the well before adding the liquid; this prevents spills when sliding the lid shut and gives ants a secure feeding raft so they don't drown before returning to the nest.

4). Close the sliding lid:

Align the lid with the guide rails and slide it fully into place until closed. This creates an enclosed, low-clearance (<0.20") dark cavity that mimics underground colony chambers, encouraging ants to feed freely while protecting the bait from household dust, pets, and accidental contact.

5). Position flush against active trails:

Place the assembled trap directly against the baseboard, wall edge, or cabinet kickplate along an active ant route. Ensure the side entrance holes align directly with their walking path, allowing worker ants to travel straight through the trap like an inline tunnel without having to deviate from their chemical pheromone highway.

6). Inspect in-situ and replenish:

Check the station every 48 to 72 hours (liquid baits will evaporate faster than gels, especially in dry rooms). Gently slide the lid open without moving or lifting the base off the floor—preserving the active pheromone trail. If the bait has been consumed or dried out, top it off with fresh gel or liquid bait and slide the lid back shut. If no ants visit after 3–4 days, relocate the trap closer to their primary point of ingress or switch bait types (sugar-based vs. protein-based).

7). Clean between bait cycles:

Slide the trap open and soak both parts in warm water with mild, unscented dish soap to dissolve dried bait and wash away dead ant pheromones or mold that can repel future foragers. Avoid scented detergents or harsh chemicals, as lingering smells will deter worker ants. Rinse thoroughly, allow to dry completely, and reapply fresh gel or liquid bait.