Reduce hive entrances during dearth periods

Narrow the hive entrance to a small opening (about 10-15 mm wide) using an entrance reducer or a simple block of wood. A smaller entrance allows the colony's guard bees to defend effectively against incoming robbers.

Why It Works

A full-width entrance on a standard Langstroth hive is roughly 375 mm (15 inches) across -- far too much territory for a weakened colony to patrol. Reducing it to a single bee-width opening forces robbers into a bottleneck where guard bees can inspect and repel intruders one at a time. Strong colonies can handle a slightly larger opening; weak or nucleus colonies need the smallest setting.

Tips

• Reduce entrances before robbing starts, ideally at the first signs of nectar dearth
• Watch for fighting, wrestling bees, or dead bees at the entrance as early robbing signs
• Use the smallest notch on a commercial entrance reducer for vulnerable colonies
• A piece of #8 hardware cloth stuffed into the entrance works as a quick field fix
• Re-open entrances once nectar flow resumes to avoid overheating and congestion