[3] They have distinctive lappets (disc-shaped protrusions), which project from the base of the ears onto the brow of the bat.

[4] I. phyllotis has an external morphology common to that of gleaning bats, and are thus well adapted for plucking stationary insects from surfaces.

[3] To do this they have long tragi and ears, wings adapted for maneuverability and hovering flight, and a gracile jaw.

[3] I. phyllotis) is the only species in North America known to emit long, constant frequency-frequency modulated echolocation calls.

[2] Allen's big-eared bat inhabits the southwestern mountainous regions of Mexico and the United States.