Prey animals such as deer and sheep sleep for 3 to 4 hours per night, and sheep typically sleep in a herd for added protection. The giraffe sleeps only about 30 to 90 minutes a day. Because getting up from the ground takes them a little time, laying down makes them more vulnerable to predators such as crocodiles and lions. For this reason, they will often sleep standing up and may rest their head on their rumps. Researchers until the 1950s believed that they didn’t sleep at all. Many prey animals sleep less than predatory animals. However, this rule does not apply to all species.
Since they are a prey species, they sleep extremely lightly and tend to nap during the day. They’ll sleep within the herd, and some sheep will stay awake whilst others to sleep to act as alarm bells in case of predators.
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