Interesting Animal - Rats

According to research from from the University of Leicester, rodents could evolve to fill niches as larger mammals go extinct.

(The largest extinct rodent known to science was Josephoartegasia monesi. It lived three million years ago, was larger than a bull, and weighed over a ton. Like its modern-day relative, the sheep-sized capybara, it lived in South America.

Gigantism is a well known evolutionary response that occurs when a small creature steps into an ecological niche left by a larger species.

Rats the size of sheep!  If that isn't a good enough reason to protect the elephant, rhino and other species from extinction, I don't know what is.)