What is an animal that never stays still?

There isn't one specific animal that never stays still. Even animals known for constant movement, like fish or insects, will rest or become motionless at times.

However, here are some animals known for their constant movement or activity:

* Fish: Fish are constantly swimming to breathe, find food, and avoid predators.

* Insects: Many insects, especially flying insects, are constantly on the move.

* Birds: Some birds, like hummingbirds, are constantly flying to feed and maintain their energy.

* Mammals: Certain mammals, like squirrels, are always scurrying around looking for food or exploring.

It's important to remember that even these animals need to rest and sleep!