Animals and Food: Heterotrophs vs. Autotrophs

The statement "animals cannot make their own food" is generally true for animals, but the biological distinction is:

• Autotrophs (Producers): Make own food via photosynthesis (plants, algae, cyanobacteria) or chemosynthesis (some bacteria). Animals are NOT autotrophs.
• Heterotrophs (Consumers): Must consume organic carbon. All animals are heterotrophs. Includes herbivores, carnivores, omnivores, detritivores.

Exceptions: Some animals host photosynthetic symbionts (corals, sea slugs like Elysia with chloroplasts), but they don't perform photosynthesis themselves. The animal kingdom is defined by heterotrophy.