These brainless jellyfish use their eyes and bundles of nerves to learn

The animals haven’t been shown to change their behavior based on past experiences, until now

A photo of a Caribbean box jellyfish on a dark background.

Fingernail-sized Caribbean box jellyfish use their 24 eyes to spot and dodge mangrove roots that might damage their fragile bodies.

J. Bielecki

For Caribbean box jellyfish, learning is literally a no-brainer.