Aedes aegypti is also an invasive species. A native of Sub-Saharan Africa, Aedes aegypti began a long association with humans when humans first moved into the African forests. Aedes aegypti was able to find suitable hosts (humans) and nearby habitat in the water collected by people. Aedes aegypti adapted to the urban environment and has lived in close association with humans since then. As trade from Europe increased, Aedes aegypti spread as larvae swimming in the casks of water brought on board the ships. Aedes aegypti had colonized much of the world by the 17th century.
Successful invasive species can pave the way for other species that depend on them. Without the spread of the mosquito, viruses such as Zika and yellow fever could not themselves become invasive.