Drongos are short-legged birds, with an upright stance when perched and they are coloured mostly black or dark grey with some having elaborate decorations on long, forked tails. They feed on insects which they often catch in flight.

Some of the 29 species (ranging through Africa, Asia and Australia) are accomplished mimics of other birds, and even mammals, and have a variety of alarm calls, to which other birds and animals often respond as warnings of the presence of a predator. Drongos utter hoax alarm calls that typically scare other animals off their food, which the drongos then eat, getting much of their food this way.

The drongos not only use their own alarm calls, but imitate those of many species, either their victim's or that of another species to which the victim is known to respond. If the call of one species is not effective, perhaps because of habituation, the drongo will try another; 51 different calls are known to be imitated.

The word “drongo” is used in Australian English as a mild form of insult meaning "idiot" or "stupid fellow". This usage derives from an Australian racehorse of the same name in the 1920s that never won despite many places, and, by transference, anyone slow-witted or clumsy became a “drongo”.

A passageway or lane, especially between walls or hedges is sometimes known in England as a “drong”. The same word in Irish means a multitude, a body of people, a throng (and drongo is not an individual from such a group).

More Info: en.wikipedia.org