Crunch! This is sound made when an African elephant chews its food. African elephants chow down between 400 and 600 pounds of plants and other greens a day. In order to break down this extreme amount of food, their teeth must be crunching all the time. This causes the teeth to be so over-used they eventually fall out. In contrast to humans, the loss of African elephants' teeth can be quite threatening to an elephants life. For them, having no teeth means starvation.
For a young African elephant, a single set of teeth can last up to three years. An adult's tooth can last up to ten years. While human teeth grow from the gum line, elephant teeth grow from the back of the mouth and move forward. When one set of teeth falls out, a new set slides forward to replace it.
Elephants go through six sets of teeth in a lifetime. If an elephant runs out of teeth, it starves to death. As veterinary dentist David Fagan put it, as important to the elephant as a heart or other major organ we need to survive, “teeth may be the most essential organ elephants have.”
[Source: National Geographic]