Why do elephants have trunks?

The trunk evolved as elephants grew larger with heavy heads and short necks, making it hard to reach the ground or high branches with their mouths. It contains no bones but tens of thousands of muscle units; a 2021 study estimated African elephant trunks have around 40,000 or more. Elephants use it to suck up water, holding several litres at a time, and spray it into their mouths or over their backs. The tip can pick up objects as small as a peanut, and their sense of smell is among the best of any animal. Trunks are also used to greet, comfort and trumpet.