PNP Trading bird nesting materials are a wonderful way to attract wild birds and encourage them to take up residence in your backyard. Our all natural materials are perfect for use by professional breeders, pet bird aviary owners and anyone interested in bird watching. Birds require various materials when nest building for the following reasons: Cushion eggs from the parents' weight and the ground Insulating eggs from variations in temperature Camouflaging and protecting the clutch from predators By using PNP Trading nesting material, you avoid the risk of introducing materials that may have been treated with pesticides, fertilizers or other potentially toxic chemicals. Synthetic fibres, such as fishing line or nylon material should not be used as they can be deadly to birds or cause injury to legs and wings.