is about 29 to 33 mm hence the common name of "bumblebee bat". It is the smallest species of bat and may be the world's smallest mammal.
It occurs in western Thailand and southeast Burma, where it occupies limestone caves along rivers.
It has a reddish-brown or grey coat and a distinctive pig-like snout.
Colonies differ in size, with an average of 100 individuals per cave. The bat feeds during short activity periods in the evening and dawn, foraging around nearby forest areas for insects. Females give birth annually to a single offspring.
Although the bat's status in Burma is not well known, the Thai population is restricted to a single province and may be at risk for extinction. Its potential threats are primarily anthropogenic, and include habitat degradation and the disturbance of roosting sites.