Red-billed quelea is sometimes called "Africa's feathered locust". The usual pest-control measures are spraying avicides or detonating fire-bombs in the enormous colonies during the night. Extensive control measures have been largely unsuccessful in limiting the quelea population. When food runs out, the species migrates to locations of recent rainfall and plentiful grass seed; hence it exploits its food source very efficiently. It is regarded as the most numerous undomesticated bird on earth, with the total post-breeding population sometimes peaking at an estimated 1½ billion individuals. It feeds in huge flocks of millions of individuals, with birds that run out of food at
Red-billed quelea and wing coverts and flight feathers have buff margins. At an age of about five months they moult again and their plumage starts to look like that of breeding adults, with a pinkish-purple bill. Different subspecies are distinguished by different colour patterns of the male breeding plumage. In the typical subspecies, "Q. quelea quelea", breeding males have a buff crown, nape and underparts and the black mask extends high up the forehead. In " Q. quelea lathamii" the mask also extends high up the forehead, but the underparts are mainly white. In "Q. quelea aethiopica" the mask does not extend