Rampant Rat and Fearless Mice

A prehistoric skull found in a museum in Montevideo, Uruguay, has led scientists to conclude that a rodent the size of a cow roamed the forests of south America four million years ago. The monster rat stood 5 ft (1.5 m) tall, was 10 ft (3 m) long and weighed almost a ton, making it 14 times bigger than any rodent alive today.

Scientists at Japan’s Tokyo University have created a mouse that is not scared of Cats. The researchers succeeded in turning off the receptors in a mouse’s brain that react to the scent of its chief predator. The result has been the creation of genetically modified mice who show no fear when coming face to face with cats.