Animal echolocation in the external ear. There are two hypotheses about the evolution of echolocation in bats. The first suggests that laryngeal echolocation evolved twice in Chiroptera, once in the Yangochiroptera and once in the horseshoe bats (Rhinolophidae). The second proposes that laryngeal echolocation had a single origin in Chiroptera, was subsequently lost in the family Pteropodidae (all megabats), and later evolved as a system of tongue-clicking in the genus "Rousettus". Individual bat species echolocate within specific frequency ranges that suit their environment and prey types. This has sometimes been used by researchers to identify bats flying in an area simply by
Food Not Bombs Not Bombs long-term goals is to help communities see what they can do in terms of increasing food self-sufficiency and security". Through the use of donated, community and locally grown food, Food Not Bombs attempts to prove that a sustainable and healthy diet for low income families who cannot always afford to eat a nutritious meal is possible by giving the tools to do so to the community. Food Not Bombs attempts to demonstrate the self-sufficient capacity among the poor through preparation of a variety of free and healthy dishes. The large public concern of mass consumerism and awareness of