What is At the molecular level, fish use?

At the molecular level, fish use tiny chemical messengers to talk and move around in water, just like you use your toys to play.

Imagine you're playing with a group of friends in a big pool. To tell each other what to do, like "swim to the middle" or "hide behind the slide", you shout across the pool. But fish don't shout; they send out tiny signals that float through the water and reach their friends.

Fish have special cells called sensory cells, which are like tiny ears and eyes. These help them detect changes in the water, just like you feel the waves when you splash around in a pool.

When they want to move or react to something, fish use molecules that float through the water, kind of like invisible messages. These molecules travel from one fish to another, helping them know where to go and what to do next.

It’s like if your toys could talk, each one sending out little notes so they all know when to move or stop playing. Fish use this every day, without even thinking about it!