What characteristics classify an organism in the animalia kingdom?

Organisms in the Animalia kingdom are characterized by being multicellular, eukaryotic, and heterotrophic, meaning they cannot produce their own food and must consume other organisms for energy. They typically exhibit complex structures and specialized cells organized into tissues and organs. Most animals are motile at some stage of their life cycle and reproduce primarily through sexual reproduction, although asexual reproduction also occurs in some species. Additionally, they have a nervous system and are capable of responding to stimuli from their environment.