The sight of a herd of capybaras feeding quietly on the banks of the River Amazon is like a glimpse into perhistoric times. With their massive square heads and heavy bodies they look more like the primitive animals of 50 million years ago than modern members of the guinea-pig family. Yet that is exactly what they are. Members of the group keep in touch with one another with throaty purr sounds.
Capybaras are found only in South America, on the shores of rivers and lakes. They inhabit a wide variety of habitats, from open grassland to tropical never very far from water.
They are big, heavy animals-the world's largest rodents-with barrel-shaped bodies and long shaggy coats. Their back legs are longer than their front legs, which gives them a lumbering, galloping run. Once in the water they are powerful swimmers. Their toes are high on the head so they remain clear of the water when swimming.
Capybaras head for the water at the first sign of danger. They can swim under water for up to 5 minutes when trying to escape from a predator.
Capybaras are complete vegetarians. They eat a variety of water plants, but their main food is grass. They have large chisellike front teeth and are efficient at cropping the short dry grass that remains after the dry season.
When Capybaras swim, they _________.
cannot see
cannot hear
hold their breath
breathe freely