Predation of livestock is an old problem that extends back over numerous countries, cultures, and centuries. Shepherds like David protected his flocks with a staff and a slingshot. Masai warriors in Kenya protect their cattle herds from lions with thorn fences and spears. Non-lethal and lethal means have long been used to discourage or kill predators, but as predators like lions, bears, tigers, and wolves become endangered and recognized for their valuable roles in ecosystems, there is a greater emphasis on predation prevention.