20 Animals That Have More Than One Stomach

Understanding How Multi-Chambered Stomachs Help These Animals Digest Their Food

Digestion is an essential biological process in all animals, allowing them to extract nutrients from food and fuel their bodies. While most animals rely on a single-chambered stomach, some species have evolved unique digestive systems featuring multiple stomachs—or more accurately, multi-chambered stomachs. These adaptations are especially useful for digesting tough, fibrous plant material like grasses, which are hard to break down.

Let’s explore 20 fascinating animals that have more than one stomach or stomach chamber, and learn how this evolutionary trait helps them survive and thrive in their environments.

What Does It Mean to Have Multiple Stomachs?

In many animals, especially ruminants, what’s often called “multiple stomachs” actually refers to a single stomach divided into several specialized compartments. Each compartment has a unique role in digesting food, from fermenting plant material to absorbing nutrients. This system is particularly efficient for animals that feed primarily on cellulose-rich vegetation.

1. Cow

Cows are perhaps the best-known example of animals with multi-chambered stomachs. Their stomach consists of four compartments:

Rumen – for fermentation
Reticulum – traps foreign objects and regurgitates cud
Omasum – absorbs water and nutrients
Abomasum – the “true stomach,” where enzymatic digestion occurs

This complex system allows cows to break down grasses that many other animals cannot digest.

2. Sheep

Sheep, like cows, are ruminants with four stomach compartments. They regurgitate partially digested food, called cud, to chew it again. This process helps them extract the maximum nutrients from fibrous plant materials.

3. Goat

Goats are also ruminants and share the same four-chambered stomach system. Goats are known for being able to eat a wide variety of plant materials, thanks to their efficient digestion and microbial fermentation in the rumen.

4. Deer

All deer species are ruminants. Their four-chambered stomachs help them digest grasses, leaves, and even woody plants. Deer chew their cud, much like cows and sheep, to aid in breaking down tough cellulose.

5. Giraffe

Despite their long necks and towering height, giraffes have a digestive system similar to cows. Their four-chambered stomachs help process leaves from tall trees, especially acacias.

6. Antelope

Antelopes are herbivorous ruminants that use their four-chambered stomachs to digest grasses and shrubs. Their stomachs allow them to survive in arid environments where nutrient-rich food may be scarce.

7. Moose

Moose, the largest members of the deer family, rely on their multi-chambered stomachs to digest woody vegetation, aquatic plants, and bark. Their rumens ferment these foods, breaking them down into usable nutrients.

8. Elk

Elk, or wapiti, are large ruminants native to North America and Asia. Their four-compartment stomach system allows them to extract nutrients from a plant-heavy diet.

9. Bison

Bison, often compared to cows, are North American ruminants with four stomach compartments. Their powerful digestive systems are ideal for processing prairie grasses.

10. Camel

Camels are unique in that they have three stomach chambers instead of four. These are:

Rumen
Reticulum
Omasum

Unlike true ruminants, camels don’t have an abomasum in the same form, but their system is still highly adapted for fermenting and digesting dry, tough vegetation.

11. Llama

Llamas, part of the camelid family, also have a three-chambered stomach. They digest their food through microbial fermentation and regurgitate cud to chew it again, similar to ruminants.

12. Alpaca

Like llamas, alpacas are pseudo-ruminants with three stomach compartments. Their digestive process is efficient enough to break down coarse grasses and other high-fiber plants.

13. Okapi

The okapi, a close relative of the giraffe, has a four-chambered stomach that helps it digest leaves and fruits in the dense rainforests of Central Africa.

14. Reindeer

Reindeer (or caribou in North America) also possess four-chambered stomachs. In winter, they rely on lichen, a tough, low-nutrient food, which their specialized stomachs can break down through fermentation.

15. Yak

Yaks are hardy, high-altitude ruminants with four stomach chambers. They graze on mountain vegetation, which is difficult to digest without the aid of microbial fermentation and multiple digestive phases.

16. Nilgai

Nilgai, also known as blue bulls, are large antelope native to India. They are ruminants with four stomach compartments and feed primarily on grasses, leaves, and shrubs.

17. Kangaroo

Kangaroos are not ruminants, but they do have a multi-chambered stomach. Their stomach has two main sections, and they ferment food in a chamber similar to a rumen before moving it to the second compartment for digestion.

18. Hoatzin (Bird)

Surprisingly, the hoatzin—a tropical bird found in South America—has a digestive system that ferments vegetation in an enlarged crop, much like a cow’s rumen. Although it doesn’t have true “multiple stomachs,” its system functions similarly.

19. Sloth

Sloths have a multi-chambered stomach, usually with two to three compartments, that helps them digest tough leaves very slowly. Their metabolism is slow, and digestion can take days or even weeks.

20. Colobus Monkey

Colobus monkeys have a complex, multi-chambered stomach adapted for fermenting leaves. They are unique among primates for this trait, and it allows them to digest fibrous plant materials that most other monkeys cannot.