Nesting materials are items that birds and other animals use to build their nests. These materials can include twigs, leaves, grass, feathers, and even man-made objects like string or paper. The choice of materials often depends on the species and the environment in which they live. For example, sparrows may use grass and mud, while eagles might prefer larger sticks and branches. In addition to birds, many mammals, such as rabbits and squirrels, also gather nesting materials to create safe spaces for their young. These materials provide insulation, protection from predators, and a comfortable environment for raising offspring. The availability of suitable nesting materials can significantly impact the reproductive success of these animals.