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1 October 2026

Imagine going to sleep without completely switching off.

One eye remains open.

Half your brain rests while the other half stays alert.

For some animals, this is not imagination. It is survival.

Dolphins can use a behaviour called unihemispheric sleep, in which one half of the brain rests while the other remains active. The eye associated with the awake side can remain open, allowing the animal to keep swimming and remain aware of its surroundings.

It also means a dolphin can continue surfacing to breathe while sleeping.

Think about that.

We usually think of sleep as surrendering ourselves completely to rest.

A dolphin cannot afford to do that in the same way.

The ocean is not a bedroom.

It is a moving, breathing world where the animal must continue to surface and remain aware.

So the dolphin has found a compromise.

Rest—but don’t completely switch off.

Perhaps nature has a strange way of solving problems that seem impossible.

And perhaps there is something rather beautiful about an animal that has learned to rest without ever entirely losing touch with the world around it.

Rajat Chandra Sarmah, Guwahati, Assam, India, Instagram @rajatchandrasarmah, YouTube: conversewithasmile, email rajatchandrasarmah@gmail.com