Red-billed Quelea live and breed in huge flocks, mostly in steppe and savanna regions, but not avoiding human settlements. While foraging for food they may fly large distances each day without tiring. Their life expectancy is two to three years.
The breeding season begins with the seasonal rains, which come at different times in different parts of their range - starting at the north-western edge around the beginning of November. The breeding males first weave half-complete ovoid nests from grass and straw. After the female has examined the construction and the mating has occurred, both partners complete the weaving of the nest. The female lays two to four light blue eggs, and incubates them for twelve days. After the chicks hatch, they are nourished for some days with caterpillars and protein-rich insects. After this time parents change to mainly feeding seeds. The young birds fledge and become independent enough to leave their parents after approximately two weeks in the nest. They are sexually mature after just one year, but many females die before this time, leaving many males without a partner.
The distribution area of the Red-billed Quelea covers most of sub-Saharan Africa, excluding the rain forest areas and parts of South Africa. They are regarded as pests by farmers because of their greed, and often compared with locusts, which fall upon grain and rice fields. Since they have hardly any natural enemies, their population is enormous, some 1.5 billion individuals. Even extreme control measures such as dynamiting the nest colonies and use of organophosphate poisons have not significantly reduced their numbers.