Fairy flies are in fact tiny parasitic wasps, the tiniest insects discovered. This one, which lives in India, measures only 0.2mm across its wings. Fairy flies lay their eggs inside the eggs of larger insects. The wasp egg hatches into a larva, which eats the host egg before it has a chance to develop. Then the larva pupates inside the empty eggshell, and turns into a fairy fly. Fairy flies are so light, they are carried by the slightest movement of air. These tiny wasps help control the populations of insects on which they live. Any problem that endangers their host insect will endanger them.
Illustration © Liz Brownlee
George McGavin looks at common wasp architecture: BBC.