Due to their species richness, the fact they are easy to collect and store in the laboratory, their relevant role as a key-stone species, and their cultural importance in some countries, crayfi sh have been-and still are-excellent model organisms for several areas of research. Of these areas, behavior occupies a signifi cant proportion of the studies produced in the last years. Crayfi sh were thoroughly investigated for social recognition, in addition to their agonistic and spatial behavior: new intriguing behavioral issues have been addressed, such as the presence of personality or the capabilities to eavesdrop and recognize individuals. As emphasized by Sutherland (1998) and Holway and Suarez (1999), the knowledge of species behavior is crucial in that it leads to an understanding of their habitat requirements, and also suggests the correct scheme that managers should follow for their conservation and their control. For example, most studies concern invasive crayfi sh species in Europe (e.g., Procambarus clarkii, Pacifasticus leniusculus) in order to establish appropriate methods for their management. Gathering information on behavior is thus particularly critical in terms of defi ning future scenarios of animal population abundance and distribution, in light of increasing global change.