Daily Facts
Nature
The dolphin that sleeps with one eye open
Dolphins never fully sleep. Their brain rests in halves: one hemisphere sleeps while the other stays awake.
During this unihemispheric sleep, one eye remains open to watch for predators and locate the surface. The other eye closes, letting half the brain recover. Every two hours or so, they switch sides.
This adaptation allows them to surface for air without interruption, even while resting. A vital necessity for these marine mammals that must regularly come up to breathe.
Source: saviez-vous-que.fr
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