Swarm Trap Volume Calculator
Scout bees are picky about cavity size. Measure your bait hive's interior in inches or centimeters and see its volume in liters and gallons, checked against the range swarms most often choose.
Measure the inside of the box. Defaults match a ten-frame Langstroth deep.
Formula & how it works
Volume is length × width × height. Cubic inches convert to liters with × 0.0163871; centimeters give milliliters, so ÷ 1000 for liters. Gallons come from liters ÷ 3.785.
The comparison band treats roughly 20–45 liters as the commonly accepted range, centred near 40 liters.
Worked example
A ten-frame Langstroth deep measuring 18.375 × 14.75 × 9.625 inches inside comes to about 42.7 liters, or 11.3 gallons — right in the preferred range. A five-frame nuc at 19 × 9 × 9 inches is about 25 liters: smaller than ideal, though swarms still occupy them.
Catching swarms
Why volume matters to scouts
Scout bees inspect potential homes carefully, and cavity size is one of the criteria they weigh. Too small and a colony cannot store enough honey to survive winter; too large and it cannot defend or heat the space efficiently. Around 40 liters sits near the sweet spot.
Repurpose what you have
A spare deep hive body makes an excellent trap because it is already close to the ideal volume and takes frames directly, so a caught swarm can be moved without disturbance. Purpose-built plywood boxes and even sturdy fiber pots work too, as long as the interior volume lands in range.
Volume is necessary, not sufficient
Even a perfectly sized box gets ignored if it is in deep shade at ground level. Mounting it a few meters up, giving it a small entrance of roughly two square inches facing away from prevailing weather, and adding old drawn comb or a lemongrass lure all raise your odds considerably.