Scout Bees Measuring or Inspecting The Volume of a
Cavity
When I was a beekeeping equipment manufacturer we were short
of space in our factory and so we made use of the 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.
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 permenantly open door, which
was always entered at about eye level and accurately central beween
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...
- 1,
- What is the significance of human eye level?
- 2,
- Why and how were the bees able to travel accurately, centrally
between vertical surfaces that were 3 feet apart?
- 3,
- 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
consistant bee to bee.)
