An animal (such as a human) that grows fur or hair from out of its skin. The females provide milk to feed their young who are usually born live.

Too small to be seen with the eye, but large enough to be seen under a microscope (a useful tool that makes tiny things appear bigger).

A group of plankton that feed on phytoplankton. Most zooplankton are so tiny they are only visible through a microscope but some are larger, such as jellyfish.

Tiny living things (organisms) that drift and float in water. Plankton can be plants, animals, or other types of organism. They are an important source of food for large sea animals such as fish and whales.