John Allan's post gives about Von Praagh's work gives another angle on John
Henry's question that must be considered, but the consideration introduces
more questions.  It is likely that John Henry's fluorescent lights were not
line- powered, or he would not have been using the other lamps.  Battery
operated fluorescent lights use an inverter, operating at an ultrasonic
frequency to convert the battery voltage to the high voltage necessary to
excite the fluorescent tube.  Thus the flicker would be about 40 KHZ, which
flicker would be smeared into constancy by the persistence of the phosphor.
Also, Von Frisch teaches that bees' response to flicker is about ten times
our own.  We have no response above 100 Hz, so bees probably cannot respond
beyond 1000 Hz.

All this does nothing to prove my guess right, because the inverter in the
fluorescent light is very likely a strong source of ultrasonic accoustical
noise and AC magnetic field.  Though many have, in the Archives, mentioned
using a tape recorder, and I also consistently use one without incident,
Item #23791 mentions bees attacking a tape recorder, which due to its bias
oscillator, might also be a source of the same sort of accoustical and
magnetic noise.

Unfortunately, it is too cold here at night for bees to fly to try this
experiment.  If John Henry, or anyone else, would repeat the exposure of the
bees to the cited light sources at night, but with one battery powered
fluorecent light giving light, and another operating, but having its
illumination obscured by an opaque material, or the same lamp first exposed
and then obscured, it might be learned whether the bees went for the light
or something else emitted by the battery powered fluorescent lamps. It would
be advisable to use the same make and model of lamps as used by John Henry
to assure a source of the same attraction.

Bill Morong