This page is credited in full to Dave Cushman who created it. His voice is expressed in black colour text and any additions or comments in blue belong to myself. Credit: Dave Cushman’s website.
Scout Bees Measuring or Inspecting The Volume of a Cavity
Observations about repetitive bee behaviour that would be considered measuring or inspection by human terminology.
When I was a beekeeping equipment manufacturer we were short of space in our factory and so we made use of the room height, which was twelve feet. We did this by building a set of shelves from angle iron that hung from the ceiling and were also joined to the walls. These were rather like mezzanine floors.
We stored Hive boxes and stacks of roofs and other hive components on these shelves, which gave rise to rectangular and square blocks of kit, separated by rectangular and square blocks of empty space. This was further complicated by a display of made up hives of all sorts of different types, on some of the shelves.
The front door was usually left open and there was a “corridor” (about 3 feet wide) between two racks and sets of shelves that led from the front door to the space surrounded by the shelves full of kit.
Bees would enter the open door at about human eye level and travel down the centre of the “corridor” mentioned above. On reaching the open space that was our packing and despatch bench they would travel to one or other of our large shelves and then “patrol” around the lumps and bumps maintaining a gap of about 100 mm to any vertical surface. The sequence of this slow flying “inspection” was random (or at least no one ever established a pattern).
Each individual bee spent between 15 and 45 minutes at this activity. Over a period of several years hundreds of bees were observed by myself and my staff. Some bees even entered empty hives that were on display. On some days odd bees would fly down to my office that was about 50 feet from the main door, this office was about 10 feet by 10 feet again with a permanently open door, which was always entered at about eye level and accurately central between the door jambs. This large space only received a cursory fly round, usually one circuit of about six feet in diameter, then out of the door very close to the point in space at which it had entered.
There were several places within the factory that we had these large high level shelves, some in multiple banks, three feet wide with gaps three feet wide between each shelf. The inspection routines were similar no matter what was on the shelves and flight between shelves was always central in the available space.
The activity was slow and deliberate and was described as “robotic” by one of my staff. There were several aspects that interested me…
What is the significance of human eye level?
Why and how were the bees able to travel accurately, centrally between vertical surfaces that were 3 feet apart?
What mechanism allows a bee to fly at a particular distance (100 mm) from a solid surface?
The explanation that I have dreamed up for this is that the wing beats create a ripple pattern of standing waves that the bee can detect by the hairs on it’s body, I stress this is pure conjecture, but it is possible.
One other aspect that it is difficult to be certain about… During the slow flying inspection routine at internal right angle corners the bee appeared to stop in mid air and turn about it’s centre of gravity rather than flying a curved transition path. But on external corners the path was curved, effectively maintaining the 100 mm distance to the vertical edge.
(The 100 mm is guessed at, but if it was 90 mm or 110 mm it was consistent bee to bee.)
My recent self hiving swarms have preferred a Langstroth poly Nuc box over a national hive three out of four times.