What is the name of the class of animals that have a stomach with more than one compartment?

Ruminants are a class of animals distinguished by having a stomach that consists of more than one compartment, typically four. This anatomical feature is essential for their unique digestive process, which allows them to efficiently break down complex plant materials such as cellulose found in grass and other fibrous feeds.

The process begins when ruminants ingest plant material, which is initially swallowed and stored in the rumen, the first chamber of their stomach. The material can then be regurgitated and chewed again, a behavior known as "rumination". After this, it passes through the additional compartments—the reticulum, omasum, and abomasum—where it is further digested and nutrients are absorbed.

This multi-compartment system allows ruminants to maximize their nutrient intake from plant-based diets, which is crucial for their energy and growth. Other animal classes, such as monogastrics, possess only a single-chambered stomach, which limits their ability to ferment and digest plant material compared to ruminants.

Herbivores, while they may include ruminants within their category, encompass a broader range of animals that eat plants, and not all herbivores have the specialized stomach structure of ruminants. Similarly,