What is a common characteristic of ruminant animals such as sheep?

Ruminant animals, like sheep, are characterized by their unique digestive system, which allows them to effectively break down cellulose found in plant materials. This system includes a complex stomach structure comprised of four compartments: the rumen, reticulum, omasum, and abomasum. This setup enables sheep to ferment and digest fibrous plant matter, which is not easily broken down by monogastric animals. The microbes present in their rumen play a crucial role in this process, breaking down cellulose and releasing nutrients that are vital for the animal's energy and overall health.

This ability to digest cellulose is essential for ruminants as their natural diet primarily consists of grasses and other plant materials that are high in fiber. Thus, the correct answer highlights a fundamental aspect of their biology and dietary habits, reinforcing why ruminants are specially adapted to their herbivorous lifestyle.