Organisms that obtain energy by feeding on other organisms are called heterotrophs.

Here's a breakdown:

* Heterotrophs are organisms that cannot produce their own food. Instead, they must consume other organisms to obtain energy and nutrients.

* Autotrophs, on the other hand, are organisms like plants that can produce their own food through photosynthesis.

There are different types of heterotrophs:

* Herbivores: Feed on plants.

* Carnivores: Feed on other animals.

* Omnivores: Feed on both plants and animals.

* Parasites: Live on or inside another organism, obtaining nutrients from their host.

* Decomposers: Break down dead organisms and waste products, releasing nutrients back into the ecosystem.

Let me know if you'd like more details about any of these categories!