Giraffe often rest while standing up, but new research shows that they lie down more often than previously thought.
When lying down, they fold their legs under their body, but mostly keeping their necks held high. Giraffe have been known to continue browsing and ruminating in this resting position.
Occasionally, and only for very short periods of normally not more than 5 minutes, giraffe can sleep with their head resting back on their rump. This is an extremely exposed and vulnerable position, hence this is only seen rarely and for short periods of time. Research in zoos has shown that giraffe go into REM sleep when in this position.