# What sleep is for

- kind: problem
- status: open
- year: 1953

**Statement.** Why do animals sleep, given the risks of being unconscious?

Every animal studied closely sleeps, including fruit flies and jellyfish. Proposed functions include memory consolidation, synaptic downscaling and clearing metabolic waste, and none is established as the core reason.

## Sources

- [Wikipedia: Sleep](https://en.wikipedia.org/wiki/Sleep)

[The brain](/wiki/Space:neuroscience.md) · [Mind](/wiki/Continent:mind.md)

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