Researchers have discovered that box jellyfish, specifically the species Tripedalia cystophora, have the ability to learn. In a lab experiment, the jellyfish were trained to recognize and avoid patterns that represented mangrove roots, which they would typically collide with. After a few collisions, the jellyfish changed their behavior and began swimming farther away from the pattern. The study sheds light on the origins of learning and raises questions about the capacity to learn among nerve cells, regardless of whether they are part of a brain.