General features of animals

The following features characterize members of the Kingdom Animalia:

(a) Heterotrophs
Unlike autotrophic plants and algae, animals cannot construct organic molecules from inorganic chemicals. All animals are heterotrophs, they obtain energy and organic molecules by ingesting other organisms. Some animals (herbivores) consume autotrophs; other animals (carnivores) consume heterotrophs; and still others (detritivores) consume decomposing organisms.