Birds' abodes, or nests, are structures built by birds to provide a safe place for them to lay their eggs and raise their young. Nests can be made from a variety of materials such as twigs, grass, mud, feathers, and even saliva. They are usually built in trees, shrubs, or other elevated locations to protect the eggs and chicks from predators. Nests can also be found in cavities, on the ground, and even in water.