Mammals include the largest animals in the world, in the sea, in the air and on land: • The bison is the largest land mammal in Canada. It can weigh almost as much as a small car. • Humpback whales sing long, complicated songs. They use these songs to communicate with other humpbacks. • A muskrat can stay underwater for about 15 minutes. It can swim the length of a football field before it comes up for air. • Bats eat while they are flying. A bat can eat up to 1000 insects in a night.