Do sonar fences exist?

[Burta]

Hello,
I was talking to a very knowledgeable commercial bee keeper and he told me that in the USA, some farms are using sonar fences to keep bees in. He advised it was used for pollination, to prevent bees from spending their time pollinating the neighbours crops.
I've tried to google it, but there isn't anything. Does anyone know anything about this practice?
Regards   Burta

[sc-bee]

I think they sell them in the hardware department, next to the bucket of steam and the sky hooks 

[BeeMaster2]

They are with the BT punch. We used to send the new bees down the Boiler room on a ship to ask for from the Boiler Technicians.
Jim

[little john]

As other have intimated, sonar fences are essentially the stuff of science fiction - but - as with all seemingly barmy ideas, there is some truth underpinning the concept.

In Britain, devices known as 'Mosquitoes' - which emitted very loud high pitched warbling noises - were installed in shop doorways etc., where gangs of youths tended to congregate at night, and with good effect ... in the sense that those youths soon moved on ... but only to congregate in other areas.

The theory underpinning this was that the high-pitched noise was audible (and thus uncomfortable) only to the young, before their ability to hear high-frequencies deteriorated with age.

It is also true that moths will avoid high-pitched sounds which they interpret as being emitted from bats.

Experiments have also been conducted on humans using low-frequency (sub-audible) sound waves, in which rooms were cleared very quickly when such sounds were generated - and no-one could ever explain their reasons for leaving the experimental room.


So - yes, the use of sound could become feasible in theory in the future, but - in practice I doubt it, in view of the height requirement for an effective outdoor 'fence'.

LJ

[sc-bee]

In Britain, devices known as 'Mosquitoes' - which emitted very loud high pitched warbling noises - were installed in shop doorways etc., where gangs of youths tended to congregate at night, and with good effect ... in the sense that those youths soon moved on ... but only to congregate in other areas.

The theory underpinning this was that the high-pitched noise was audible (and thus uncomfortable) only to the young, before their ability to hear high-frequencies deteriorated with age.

I like that idea... my kids got a kick out of this fact when we could not hear their cell phones set to this pitch. Students in class would also use it so the teachers could not hear it.


So - yes, the use of sound could become feasible in theory in the future, but - in practice I doubt it, in view of the height requirement for an effective outdoor 'fence'.

That was my first thought.

LJ