The Web of Life (110) Rodents


40% of mammal species are rodents. With 56 million years to make their mark, rodents are found in vast numbers everywhere but Antarctica.

Like humans, rodents breed at an appalling rate. Likewise, every rodent has its own personality. In the face of stress, some mice have passive personalities, and so appear stoic, while the proactive put up resistance.

With one exception among 2,200 species in 27 families, rodents must gnaw, as their 2 front teeth grow all the time. As a rodent gnaws, its incisors scrape together, keeping them sharp. Rodent molars, the chewing teeth, are set far back into the jaw, affording the strongest possible bite.

The gnawing exception is a forest-dwelling shrew-rat, with oddly shaped incisors and no molars. The shrew-rat’s mouth adapted to its favorite food: soft-bodied earthworms that need to be nabbed but require little chewing.