Megabat long, thus smaller than some microbats, for example, the Mauritian tomb bat. The largest attain a wingspan of , and weigh as much as . Most fruit bats have large eyes, allowing them to orient themselves visually in twilight and inside caves and forests. Their sense of smell is excellent. In contrast to the microbats, the fruit bats do not use echolocation (with one exception, the Egyptian fruit bat "Rousettus egyptiacus", which uses high-pitched tongue clicks to navigate in caves). Megabats make up the only family (Pteropodidae) in order Chiroptera that is not capable of laryngeal echolocation. Echolocation and flight
Generally recognized as safe substance does not qualify for the GRAS exemption, that use of the substance is subject to the premarket approval mandated by the Federal Food, Drug, and Cosmetic Act. In such circumstances, the FDA can take enforcement action to stop distribution of the food substance and foods containing it on the grounds that such foods are or contain an unlawful food additive. Generally recognized as safe Generally recognized as safe (GRAS) is an American Food and Drug Administration (FDA) designation that a chemical or substance added to food is considered safe by experts, and so is exempted from the usual Federal