Swarm Trap Cap

Swarm Trap Cap

Inspired by a product for sale that I am too cheap to buy, this is an entrance for a honeybee swarm trap. It allows for the sealing of bees within a swarm trap so they can be moved to your apiary. The vented cap provides some level of airflow to the bees while in transit.

Features

• 34mm (1 5/16") entry hole

• Threaded cap with 3mm vent holes

• Bird guard

• Bait cup for swarm attractant

• Mounting holes for #8 wood screws

Usage

1. Attach over entrance of swarm trap using 3/4" #8 wood screws.

2. Apply swarm lure (like lemongrass oil) to a cotton ball or sponge. Place inside the closed-bottom cup.

3. Screw vented cap over the bait cup, securing the cotton ball.

4. Wait for a swarm to move in!

5. At night, unscrew the cap from the bait cup, and screw it on over the open-hole entrance. The bees are now secured inside and ready to be moved.

Tips

• For best results, print in UV reactive blue filament as this has been shown to be most attractive to swarms. I use ABS to withstand the heat of the sun, some others use PLA.

• When sealing bees in, spray the entrance with a little plain water to stop bees flying out while you fumble around putting the cap on.

Also provided is the FreeCAD file. Have fun remixing to suit your needs. Some ideas for remixes include stylized vent holes, queen excluder slots, or entrance reducing holes.

May 2026 Update:

This design works great. All my traps have already caught multiple swarms this year, to the point that I am running out of equipment.

The Good:

• The threaded cap doesn't get stuck like some of the disk style entrances do, making for a much smoother and calm experience for the bees.

• Keeping the lure on the outside of the trap is beneficial, it's just enough to draw them in without the risk of the lure being too potent and putting them off.

• The "tube" coming off the entrance seems to be appealing. More scout bees go right for the entrance instead of surveying the outside of the trap. The depth/contour of the entrance removes any doubt of where the front door is.

The Bad:

• Both lemongrass oil and Swarm Commander will eat away at ABS plastic. Maybe due to limonene content? Not enough to cause structural failure, but the cotton ball holding the lure gets semi-fused to the plastic. PLA should be fine to use.