Lasiurus ega occurs in a variety of habitats, in both mesic and xeric forests (Kurta and Lehr 1995). In Venezuela, this bat lives in tropical dry forest, subtropical moist forest, and tropical moist forest (Handley 1976). Mostly, these bats roost in trees, generally hanging from the midrib of a leaf, and among dead fronds of palms trees, but also in building crevices or holes. In the U.S. L. ega is associated with introduced palms, which is thought to be a reason for its recent expansion northward. They can be found alone or in groups with up 20 individuals. They can be found in degradeted areas and roofs made with palm (Barquez et al. 1999). In Mexico, this bat apparently eats beetles more frequently than other preys (Kurta and Lehr 1995).

The species is found in Southern Texas, Eastern and Southern Mexico south to Bolivia, Argentina, Paraguay, Uruguay, and Brazil; Trinidad (Simmons 2005). Also found in Colombia, Venezuela, Guyana and Suriname, but not in Chile or French Guiana (Gardner and Handley 2008).

Occurs in protected areas in Belize and Mexico, also in Colombia and Venezuela, Peru and Bolivia, and probable in private natural reserves along its extensive range.