Definition
Delichon urbica, or the common house martin, is a small migratory bird that builds mud nests on buildings. These birds are aerial insectivores, meaning they catch insects while flying. Think of them as tiny, winged cleanup crews for bugs. They're social birds, often seen in flocks, especially during migration. Their neat nests are usually found under eaves. These birds contribute to urban biodiversity. They are smaller than swallows but bigger than swifts.