BIRD HABITATS Birds build nests. Nests keep eggs safe. Nests keep birds safe. Nests provide shelter. Some birds build nests on the ground. Some birds build nests in trees. Some birds find shelter inside trees. Some birds build nests on the water. A nest is a safe habitat, where baby birds grow. What can we learn from how animals engineer their homes? Weaver birds use grass to build a nest. This roof is built with grass and leaves. Animals can find shelter in the mud. This home is built with mud. Animals find shelter in caves. This home is built inside a cave. Animals find shelter in the snow. Igloos are made of ice and snow. Animals make their homes underground. This home is underground. Animals make their homes from wood. This home is built with wood. We can learn how to build safe shelters.