The southern little yellow bat is a small aerial insectivore. It has been recorded hunting flying insects along forest trails, in clearings, and over water, but the boundaries of this broadly defined taxon remain under review.
One subadult male recorded in southeastern Peru had a light-brown back, pale-yellow belly, and inconspicuous muzzle pads.
It catches insects in flight and has been netted along forest trails, in clearings, and over streams or pools. Foraging is thought to occur mostly within a few meters of the ground.
An extinction-risk assessment has not been added yet.