 The female lays the eggs vertically and side by side, held together by a sticky substance excreted to coat the eggs, head end down, creating an egg raft that is convex below and concave above with ends that are typically upturned.Species that use this form of egg-laying typically hatch as first instar larvae within a few hours of laying.Oviposition on the surface of stagnant water is most common, but some species of "Aedes" and all "Psorophora" deposit their eggs in areas that will flood.