1. They are multicellular: Animals are made up of many cells that work together.
2. They are heterotrophic: They cannot make their own food and must obtain it from other organisms. This means they eat plants, other animals, or both.
3. They are eukaryotic: Their cells have a nucleus that contains their genetic material.
4. They are capable of movement: Even if it's only in their larval stage, all animals are able to move at some point in their life cycle.