Why do poachers use poisonous cyanide?
On Wednesday we reported that poachers have killed 41 elephants in Zimbabwe's Hwange National Park by poisoning them.
It's thought cyanide poison was spread in the elephants' habitat to kill them, so poachers could take their tusks.
We spoke to Charlie Mayhew from charity Tusk to find out why poachers are using poison.
He told us that poisoning elephants lets poachers silently kill elephants without alerting the authorities.