Cattle can sometimes defeat virtual guards. A rancher in Queensland, Australia, told a reporter that after some of his old bulls leaped a painted grid, the younger ones lost their fear of walking across. This is common; if one member of a herd discovers it can step safely on the lines, others will follow. Other incentives that lead cattle to test a virtual guard include placing food on the opposite side, or using strong driving pressure to run panicked cattle over a virtual grid.