Biology is a science about the things that are alive. There are lots of different things that are alive, like plants, animals, and even tiny things you can't even see without a special kind of microscope. Scientists who study living things are called biologists, and they spend their time learning about what living things need to survive, and how they change over time. When biologists study a living thing, they look at how it grows, what it eats, what it looks like, and how it moves. They also look at how the living thing is similar to other living things and how it is different from them. By understanding how living things work and interact with their environment, biologists can understand how life came to be on Earth and how it continues to change.