Here's why:

* Nerve cells (neurons): Neurons are specialized cells that transmit signals throughout the body. They do this through electrochemical impulses, allowing for rapid communication between different parts of the body. This communication enables animals to respond to stimuli, control movements, and process information.

* Other cell types also contribute to communication: While neurons are the primary message carriers, other cell types, like glial cells, support and protect neurons, and hormones travel through the bloodstream to deliver messages.

Let me know if you'd like to learn more about how neurons work!