Early Humans for Kids
What is an ice age? An ice age is a period of time when much of earth's water is frozen in glaciers. Throughout time, the earth has experienced several ice ages. Things become cold, and then the weather warms up again. Each ice age takes many thousands of years to cycle. During an ice age, oceans become smaller and lower, as the water freezes into glaciers. This uncovers land. Giant walkways of frozen ice also appeared during the last ice age over what would become vast rivers and seas.
During the last ice age, land bridges appeared between Africa and Europe and Asia. Using these land bridges, early humans migrated out of Africa, probably following herds of animals.