Bird nests are structures built by birds to hold their eggs and raise their young. They can be made from various materials, including twigs, grass, feathers, and mud. The design and location of nests vary widely among different species, with some birds nesting in trees, while others prefer ground or cliff locations. Nests serve several important functions, such as providing protection from predators and harsh weather. Some birds, like sparrows, create simple cup-shaped nests, while others, like weaver birds, construct intricate woven structures. The type of nest often reflects the bird's habitat and lifestyle, showcasing the diversity of avian adaptation.