Sea urchins' ballistic escape from predators

New research shows that sea urchins, albeit having a limited and ancestral sensory system, can show a complex behaviour when escaping a predator. These marine invertebrates tend to move slowly and with unpredictable movements, but when they smell a predator, they escape following a ballistic motion -- straightforward, quick and directional -- to escape the threat.

source https://www.sciencedaily.com/releases/2021/11/211111130408.htm