ABSTRACT
All living beings can communicate among themselves, if for no other reason than to guarantee the continuation of the species. Indeed, a minimal level of communicative competence is necessary in order to procreate in all those species in which collaboration between male and female is indispensable for the generation of offspring. The capacity to communicate, however, varies greatly within the various species of animals. Broadly speaking, we may distinguish between three different classes of communications systems: closed systems, semi-closed systems and open systems.
