Muscles are like rubber bands inside your body. They can stretch and squeeze to help you move. When you want to pick up a toy or run around, your muscles help you do it by getting shorter and longer, just like when you pull and release a rubber band. Muscles are very helpful because they make your arms, legs, and other body parts move.
Think of muscles as tiny engines inside you. Just like a car needs an engine to go, your body needs muscles to move. When you want to jump, your muscles get busy like little engines, giving you the power to push off the ground. These engines need fuel, which comes from the food you eat, to keep them running strong.
Muscles can also be like puppets on strings. Your brain is the puppet master that tells the muscles what to do. If you want to wave your hand, your brain sends a message to the muscles in your arm, and they pull the strings to make your hand move. This teamwork helps you do everything from smiling to dancing.