In the barren wastes of USA or Oztralia, thousands of miles of fences need to be put up and maintained to keep cattle and sheep in. Expensive and time consuming.
My notion is to have the bull or ram wearing a GPS receiver which is attached to a shock device or other aversive stimulus.
The GPS is then programmed to activate the device and stop the cow/sheep going further whenever it goes to or past where the real fence would have been - in effect a virtual fence. This would save a fortune in fencing costs and maintenance.
(less usefully, it could be used with cats and dogs to stop them going to next door or on the road chasing cars). An anti-barking collar which puffs a lemon smell already works pretty well. Like with the cows or sheep, it's the immediate "negative reinforcement" (OK, punishment) that counts.)-- mkirksmith, Dec 11 2001 Instant Fence http://www.technosc...te=85393&sourceid=0Sort of Baked. Lots more halfbaked ideas at this site too. [hippo, Dec 12 2001, last modified Oct 04 2004] PeterSealy: Baked as written though, with the GPS and everything?
A potential problem would be the amount of labor required to regularly track down all the cattle and replace the batteries in the shock devices.-- PotatoStew, Dec 12 2001 Since flocks of sheep are prone to run off cliffs when startled, I don't think charging through a region of electric pain would necessarily make them turn back. In such a situation, keeping on running might be more rational if no one's explained about a fence to you.
Electric fences act as a physical barrier as well as a deterrent. Without that form of instruction/explanation, the sheep could easily just choose to charge on, bleating a lot. It'd make the Silence of the Lambs sound like, well, silence.-- pottedstu, Dec 12 2001 It hasn't been done, Peter. All the ways that work for dogs and cats require either a physical wire to be put down that gives off the trigger signal. Hippo's link to 'instant fence' is an antenna that gives out a signal that keeps the collar from zapping, until they get out of range. Neither of which are what he posted.
As pottedstu says, though, the physical barriers are necessary too. I doubt a little 'zzt would stop a stampede...-- StarChaser, Dec 12 2001 random, halfbakery