What observation of hydra behaviour suggest some kind of coordination?

Observations of hydra behavior, such as their ability to coordinate movements when responding to stimuli, suggest a form of communication or coordination among their cells. For instance, when one part of a hydra is stimulated, surrounding cells often respond in a synchronized manner, allowing the organism to retract or extend its body efficiently. Additionally, their ability to orient themselves and move towards light or food sources indicates a level of sensory integration and coordinated response. These behaviors imply that hydra possess a primitive form of coordination, likely facilitated by their simple nerve net.