A new device uses the global positioning system to determine a cow' s location and, when a cow strays outside of its pasture, makes noises in the cow' s ears to steer it back to its home range  Outfitting all of the cattle in a herd with this device is far more expensive than other means of keeping cattle in their pastures, such as fences
The device' s maker nevertheless predicts that ranchers will purchase the device at its current price
As they graze, cattle in a herd follow the lead of the same few members of the herd.