It's a Math World for Animals£¨1£©

Birds do it.Dogs do it.Even salamanders do it.

The ability to solve math problems is showing up in all sorts of unlikely creatures.From monkeys who know the difference between 2 and 3 to dogs who can calculate the fastest route,animal mathematicians are teaching scientists a few things about numbers.

A growing body of research suggests that nature probably discovered math long before people did.Studies of animal mathematicians might help explain how people learn to add,subtract,and multiply and indicate what types of math people can do without going to class.Watching animals solve problems could also make math more fun for people who say they can't stand the subject.

Mathematician Tim Pennings,for instance,was at the beach when he discovered that his dog Elvis could do a type of math called calculus.

¡°I would throw a ball into the water,¡±Pennings says.¡°I noticed he'd run along the beach and then jump into the water and swim at an angle toward the ball.¡±That's a good strategy.Swimming is slow compared with running,so swimming all the way to the ball would take longer even if the route is more direct.On the other hand,running along the beach adds to the total distance Elvis must go to get to the ball.The best bet is a compromise between the two-running a certain distance along the beach before plunging into the water.