Diatomaceous earth is a type of powder made of tiny pieces of fossils called diatoms. Diatoms are tiny pieces of shells from single-celled plants that lived in water millions of years ago. Because of their small size, diatomaceous earth is very light and silky to the touch. It can be used in many different ways. For example, it's often added to things like toothpaste because it can help to keep your teeth clean. It's also used in gardening to help keep away bugs that might damage plants. Finally, it can be used around the house to help absorb odors and moisture.