The 1st-century Roman historian, Pliny the Elder and Claudius Aelianus, a 2nd-century writer, describe that one of the best defences against elephants was pigs. Their smell made the animals panic.
This, in turn, meant a deadly danger for his own army, as the scared elephant trampled everything on the road.
It was for this reason that the mahouts had with them a special chisel, which, in the event of losing control of the animal, would stick it into its spinal cord, causing it to die quickly1.