I always had the feeling that humans are the only beings who can filter water. But how wrong was I.

Scientists studying animal behavior in Senegal say they have discovered colonies of chimpanzees and baboons which have learnt to filter water. At a seminar in Paris organized by the Society for Primatology, the scientists suggested that the filtration process worked out by animals made the water safer to drink.

They found that the apes were avoiding muddy pools in dried out river beds, and instead were taking the water from holes they had dug in the sand nearby.

Tests showed that the muddy water contained germs that made it unfit to drink, while the water filtered through the sand was germ-free.