One effect of huge increase in people living in urban areas like Kano, Lagos and Onitasha (Nigeria) is the rise of the megacity, which is a city that has more than 10 million inhabitants. Urban sprawl is when the population of a city becomes dispersed over an increasingly large geographical area. This movement from higher density urban cores to lower density suburbs means that as cities expand, they often begin to take up significant tracts of land formerly used for agriculture. Sprawl also increases the need for travel infrastructure, such as roads, because people’s homes are likely to be farther away from their working places and the amenities needed for daily use.