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 from northern and central Sudan and central Ethiopia in May and June, to breed in southern Sudan, South Sudan, southern Ethiopia and northern Kenya, moving back north from August to October. In southern Africa, the total population of the subspecies "Q. quelea lathamii" in October converges on the Zimbabwean Highveld. In November, part of the population migrates to the northwest to northwestern Angola, while the remainder migrates to the southeast to southern Mozambique and eastern South-Africa, but no proof has been found that these migration cohorts are genetically or morphologically divergent. The red-billed quelea is regarded as the most numerous