The big free-tailed bat (Nyctinomops macrotis) is a bat species found in South, North and Central America. They have a wingspan of 435 mm and an average length of 140 mm. This bat frequents rocky or canyon country where it roosts in crevices. This migratory species is a swift, powerful flier, and occasional individuals wander as far north as Canada. Little is known of mortality and longevity. Breeding probably occurs in midwinter while the species is in warmer latitudes. A single young is born in mid-June to early July. Females form small nursery colonies, and the young do not leave the nursery until they are almost full grown. Moths seem to be the mainstay of their diet, although few data have been collected. This bat emerges late in the evening and forages at high altitudes.