[LabofOrnithology]
Bird parents build nests of all different shapes and sizes to keep their young safe and warm. Bald Eagles, for example, build massive structures out of twigs that can be over 5 feet in diameter. Hummingbirds, such as this Cuban Emerald have a much more discreet approach. The cup-shaped nests they construct out of materials such as leaves and spiderwebs are only slightly bigger than a quarter and typically house two eggs weighing less than a gram a piece.