Flight Path Guides

Hive entrance diverters are the parts that determine where and how bees enter the hive: the landing board, the multi-position entrance disc, the upper entrance, the robbing screen, and the colours and markings that help bees tell hives apart all belong to this group. Their purpose is to ease traffic, reduce bees entering the wrong hive (drifting) and confuse robbers. Used correctly, they also reduce the spread of disease and differences in strength between colonies.

What does an entrance diverter do?

A forager returns to its hive dozens of times a day and finds the entrance by landmarks, colours, shapes and scent. Entrance diverters support this orientation behaviour or deliberately confuse it:

• Landing and traffic: They give a returning, loaded forager a place to land and reduce congestion in front of the entrance.
• Reducing drifting: In hives lined up in long, straight rows of the same colour, bees often enter the neighbouring hive. This strengthens the hives downwind and at the ends of the row and weakens those in the middle; mites and pathogens are also carried this way.
• Confusing robbers: Moving the entrance away from the hive mouth lengthens the route for a foreign bee following the scent.
• Flexibility: They make it possible to choose different entrances (lower, upper, ventilation, closed) on the same hive.

What is a landing board?

A flat or sloping surface extending out in front of the entrance, on which the bees land. Most floors have a short landing board; some beekeepers add a separate sloping ramp in front of it.

• Loaded return: Bees weighed down with nectar and pollen, especially on windy days, land on the board and walk in.
• Bees on the ground: A sloping board running from the ground up to the entrance helps tired bees that have fallen to the ground climb back to the hive.
• Observation point: Bees carrying pollen, dead bees being removed, faecal spotting and crawling bees are first seen on the landing board.

It also has drawbacks: a long landing board can become a hunting ground for frogs, lizards and wasps, and it offers robbers a convenient landing strip. For this reason the landing board should be short and easy to clean.

Multi-position entrance discs and hole entrances

These are round metal or plastic discs, used especially on nucs, splits and upper entrances, that are rotated into different positions. Typical positions:

1. Fully open: Normal traffic.
2. Excluder: Lets workers through and keeps the queen inside (outside the mating period).
3. Ventilation: A perforated or meshed position; bees cannot pass, but air can. For moving and closing.
4. Closed: For closing for short periods.

A few round holes drilled in the front of the hive serve a similar purpose: the entrance width is adjusted by opening or closing holes. Round holes are narrow points that are easy for guard bees to defend.

When is an upper entrance used?

An upper entrance is a second entrance made through a notch in the crown board, a hole in the front of the upper box, or the gap between the roof and the crown board.

• During a honey flow: Foragers reach the honey super directly without passing through the excluder and the brood box; traffic in the brood box is reduced.
• Drone exit: Drones left above the queen excluder can get out.
• In winter: When the lower entrance is blocked by snow or dead bees, the upper entrance provides both an exit and a route for moist air to escape.
• Caution: In a weak colony or during the robbing season, a second entrance is hard to defend; the upper entrance should be closed at these times.

How does a robbing screen redirect traffic?

A robbing screen closes off the hive's main entrance with a fine mesh screen and gives the bees a new entrance, usually at the top or side of the screen. The colony's own bees learn the new route within a day or two. A robber bee, however, picks up the hive's scent at the original entrance, hits the mesh and struggles to find the new entrance. For this reason a robbing screen is both a protective and a redirecting part; it is very valuable for weak colonies, new splits and the period after the flow.

How can drifting be reduced?

Bees entering a neighbouring hive (drifting, straying) is especially common in long, straight rows of hives, in hives of the same colour and shape, and during young bees' first flights. Simple orientation measures make a big difference:

1. Colour and markings: Paint the hive fronts different colours or put different geometric shapes above the entrance. Bees distinguish blue and yellow shades well; red, however, looks dark to them.
2. Layout: Place hives in small groups, crescents, curves or pairs instead of one long row.
3. Different directions: Turn the entrances of neighbouring hives in different directions.
4. Landmarks: Place hives among natural landmarks such as trees, bushes and stones.
5. Nucs and splits: It is particularly important that the entrances of mating nucs are clearly distinguished by colour and direction, so that the queen returns to the right box after her mating flight.

Common mistakes

• Lining up dozens of hives of the same colour in a straight, close row.
• Leaving an upper entrance open on a weak colony.
• Leaving a long landing board covered in grass and dirt; it becomes a refuge for pests.
• Moving a hive, or changing its entrance direction, by a few metres in mid-season; the foragers return to the old spot and are lost.
• Forgetting the entrance disc in the excluder position and preventing the mating flight.