In addition to the usage of sound for communication, a wide range of insects have developed chemical ways for communication. These chemicals, termed semiochemicals,are often derived from plant metabolites contain those meant to attract, repel and offer other types of information. Pheromones, a type of semiochemical, are used for attracting mates of the opposite sex, for aggregating conspecific individuals of  both sexes, for deterring some other individuals from approaching, to mark a trail,and to trigger aggression in nearby individuals. Allomonea benefit their producer by the effect they have upon the receiver. Kairomones benefit their receiver instead of their producer. Synomones benefit the producer and the receiver. While some chemicals are targeted at individuals of the same species, others are applied for communication across species. The usage of scents is especially well known to have developed in social insects.