The Bumblebee Bat Weighs Less Than a Penny

Imagine a mammal so small it could comfortably perch on your thumb. The bumblebee bat, scientifically known as Kitti's hog-nosed bat, holds the remarkable distinction of being the world's smallest mammal by body length. Weighing in at a mere 1.7 to 2 grams and measuring just 29-33 millimeters from head to body, this tiny creature is lighter than a US penny, which tips the scales at 2.5 grams.

Found exclusively in limestone caves along rivers in western Thailand and southeast Myanmar, the bumblebee bat is as rare as it is tiny. In Thailand, the entire population is restricted to a small region of the Tenasserim Hills in Kanchanaburi Province. These miniature mammals roost in small groups within cave crevices, emerging at dusk to hunt for insects in the surrounding bamboo forests and teak plantations.

A Pig-Nosed Wonder

The bumblebee bat's alternative name—Kitti's hog-nosed bat—comes from its distinctive appearance. Its snout resembles a tiny pig's nose, with large nostrils and no visible tail. The bat's reddish-brown or gray fur and oversized ears give it an endearing appearance that belies its status as a skilled nocturnal hunter.

Despite their diminutive size, these bats are powerful fliers. They use echolocation to navigate and hunt, emitting high-frequency sounds that bounce off insects and cave walls, creating a sonic map of their environment. Their diet consists primarily of small flies and other insects captured during brief foraging flights.

Smallest Mammal—With an Asterisk

While the bumblebee bat claims the title of smallest mammal by length, there's a close competitor: the Etruscan shrew. This tiny shrew can weigh as little as 1.2 grams, potentially making it lighter than the bumblebee bat, though its body length of 36-53 millimeters is notably longer. The debate over which deserves the "smallest mammal" crown depends on whether you measure by weight or length—either way, both are absolutely minuscule.

An Endangered Treasure

The bumblebee bat is classified as near-threatened by conservation organizations, and its future remains uncertain. With such a restricted range and specific habitat requirements, these bats are vulnerable to:

• Cave disturbance from tourism and limestone quarrying
• Habitat loss from deforestation of surrounding forests
• Small population size making them susceptible to disease or natural disasters
• Limited genetic diversity due to isolated populations

Discovered only in 1974 by Thai biologist Kitti Thonglongya (hence the scientific name), the bumblebee bat remains one of the world's most enigmatic mammals. Researchers estimate the total population at only a few thousand individuals distributed across roughly 35 known cave sites.

The bumblebee bat serves as a powerful reminder that some of nature's most remarkable creatures come in the smallest packages. This penny-weight mammal, clinging to existence in a handful of Thai and Burmese caves, represents both the incredible diversity of life on Earth and the fragility of species with highly specialized needs. Protecting these tiny bats and their limestone cave habitats isn't just about saving a single species—it's about preserving an entire ecosystem that has existed for millions of years.