Bacteria

microorganisms · single-celled · ancient life

Smallest living things. Bacteria are so tiny that you need a microscope to see them, measuring just a few micrometers in length. Despite their size, they are complete, functioning organisms.

Everywhere on Earth. Bacteria live in seemingly impossible places like hot springs, deep underground, frozen soil, and even radioactive waste. They thrive in nearly every habitat on our planet.

Nature's recyclers. Bacteria break down dead plants and animals, returning nutrients to the soil so new life can grow. They also pull nitrogen from the air and make it usable for living things.

Energy from chemicals. In extreme underwater environments near hot vents, special bacteria convert chemicals like hydrogen sulfide into energy that feeds entire communities of creatures.

Living with others. Bacteria form relationships with plants and animals, sometimes helping them (like bacteria in your gut that aid digestion) and sometimes causing harm.