What are external stimuli?

External stimuli are things from outside that make you notice something and react to it.

Imagine you're playing with your favorite toy, and suddenly a loud noise happens, maybe a dog barked or someone dropped a glass. That noise is an external stimulus, because it came from outside and made you look up or jump.

Think about riding in a car. When the car hits a bump, your body feels it, that's another kind of external stimulus. Your brain says, "Hey, something just happened!" and you might even say "Whoa!"

• The sun shining on your face in the morning is an external stimulus.
• A friend tapping your shoulder to get your attention is also an external stimulus.

These things come from outside of you, and they help you know what's going on around you, like a friendly reminder that the world is full of interesting changes!