Book 33, Question 4
About how many kinds of mammals are known to science?
That sounds like a lot, but there are many more kinds of birds, fish, and insects.
Scientists know of about 6,500 kinds of mammals. Mammals live on land, in the sea, in the air, and underground. They range from tiny shrews to enormous elephants. New mammals are still found now and then, especially small ones that hide in forests.