The Boy in the Submarine – Season 3, Episode 11: Blue Whales

Blue Whales are the largest animal that has ever lived! They get to 30.5 meters, and can be as heavy as 181,000kg (400 tons). They have tongues the size of an elephant, hearts as big as a car, and blood vessels a kid could crawl in.

For such a big creature their food is very small: they eat krill, plankton, and shrimp: as much as 3,600kg (8000lbs) every day by sucking them into their huge mouths, then spitting the water back out so that their food gets caught on the back of the baleen they have instead of teeth. They then lick their food off the back of their teeth.

Not are they the biggest creature in the world, they are the second loudest, too. Only the Sperm Whale gets louder.

Blue Whales swim up and down every Ocean except the Arctic following the plankton and krill that they eat through the seasons, They dive to catch their food, and can hold their breath for 90 minutes, while diving as deep as 500m. (1600 feet) although they prefer to dive 100m deep or less.