Whales Fab Fact 3: blue whales are big!
The blue whale is one of the biggest animals that ever lived on earth.
It grows up to 30 metres (98 feet) long and can weigh over 150 tonnes (165 tons).
Despite their enormous size, very little is known about blue whales. Their routes through the ocean are a mystery, and so is where they go to breed.
During the 20th century, whale hunters killed about 350,000 blue whales. Today there are about 2000 left on the planet.