Here's why:
* Safety: Lying down makes them vulnerable to predators.
* Efficiency: They can conserve energy by only sleeping for short periods, usually just a few minutes at a time.
* Their legs: Giraffes have a unique circulatory system in their legs that helps prevent blood from pooling and making them faint when standing for long periods.
Giraffes typically sleep for about 30 minutes a day, in short bursts. They often rest their heads on their necks or even on their backs!