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.](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2023/09/092123_MT_jellyfish-learning_box-jellyfish_feat.jpg?fit=1030%2C580&ssl=1)
Fingernail-sized Caribbean box jellyfish use their 24 eyes to spot and dodge mangrove roots that might damage their fragile bodies.
J. Bielecki