Fairy flies, Fairy wasps. The world's smallest insects. They are parasitoids of other insect's eggs. They usually have nonmetallic black, brown, or yellow bodies.
The antennae of the females are distinctively tipped by club-like segments, while male antennae are thread-like. Their wings are usually slender and possess long bristles,
giving them a hairy or feathery appearance, although some species may have greatly reduced stubby wings or lack wings altogether.
They can be distinguished from other chalcid wasps by the H-shaped pattern of sutures on the front of their heads. (source Wikipedia)