The clear-winged woolly bat is a small vesper bat, typically weighing about 4.5 g, that mainly forages in the understory of tropical forests in Brunei, Indonesia, Malaysia and the Philippines. It has an unusual variant of echolocation, with higher intensity and lower frequency than most other Kerivoula calls; its short-range calls are distinguishable from long-range orientation calls by peak frequency and duration (Wikipedia, general species account).
Description: Wildlife of Malaysia guide, Wildlife of Everywhere (wildlifeofeverywhere.com); general species information paraphrased from Wikipedia (CC BY-SA)
Mammals of the World