Male cockroaches can sense the spatial distribution of female pheromones to locate a mate, according to researchers from Hokkaido University and the University of Konstanz. Cockroaches are nocturnal and heavily rely on olfaction for finding food and mating partners in the dark. However, plumes emitted from an odor source are not smooth or continuous, and have no clear concentration gradient. They are rather composed of filaments (clusters of odor molecules) of various sizes (> mm) and concentrations interspersed with regions of clean air.