Whales, porpoises and dolphins also have blow holes on the tops of their heads to breathe air. There are special valves that close when the animal is under water to stop water getting into its lungs. Matriarch is the female leader of a group of animals. However, some species are led by an experienced female, such as the elephant. For more information about the elephant look at Animal Fact Sheet number 10.
Meanders are u-bends formed by rivers as they wind their way along towards the sea.
Metamorphosis is the dramatic change of an insect larvae or young animal into its adult form. For example an adult frog lays jelly eggs which develop into tadpoles, before metamorphosiing into adult frogs. Some insects such as bumblebees, moths, butterflies, wasps and beetles hatch from eggs into larvae, form into pupa and finally develop into adult insects. For more information about the bumblebee find Animal Fact Sheet Number 1. The Northern Hemisphere is the entire area of the world north of the equator and includes Europe, Russia, North America, North Africa and Asia.