View larger image | Because of their loner nature, asocial mosquito fish tend to spread to new territories. But an all-loner blend is not the best for taking over new waters. Loners keep moving so they don’t build up big numbers (top). At the other extreme, a group of social mosquito fish tend to clump close to home (middle). But in a social-asocial mix (bottom), loners reach new territories and social followers build up the populations there. Source: J. Cote et al/Proc. Royal Soc. B 2011 Credit: T. Dubé