Even a frog can spring a surprise

WASHINGTON: They were long thought to be easy prey for predators. But at least 11 species of African frogs carry a built-in concealed weapon: claws that can sprout out on demand to fight off attackers.

US researchers on Monday reported that when threatened these frogs can puncture their own skin with sharp bones in their toes, which they then use to claw their attackers.

David Blackburn, graduate student, and his colleagues at Harvard University said in a statement: "It's surprising enough to find frogs with claws."