The Bumblebee Bat or perhaps more correctly Kitti's Hog-nosed Bat, (Craseonycteris thonglongyai) is the worlds smallest species of bat at 29-33 mm in length and a weight of 2 grams (about as much as a dime). It is the only known species in its genus and is found in a tiny region of western Thailand, at Sai Yoke in the Kanchanburi province.
Bumblebee's skull
The Bumblebee Bat is named a bumblebee bat because it is about the size of a bumblebee. And a bumblebee is small. Try being a bat and being that small. It competes with the Etruscan Pygmy Shrew for the title of world's smallest mammal. At issue is whether skull size or mass defines "smallest"; the shrew is lighter but the bat's skull, shown left, is smaller at 11mm.
The Bumblebee Bat has reddish-brown upperparts, although the species seems to occur as another colour phase that has greyer upperparts. The underside is always a paler version of the top. The ears are relatively large and extend beyond the rather pig-like snout when lying forward.
They are most active at dusk when they fly around the tops of bamboo clumps and teak trees to feed on insects. The wings are quite long and broad with pointed tips and dark membrane. They seem to be shaped for hovering flight and indeed gut contents of specimens do include spiders as well as other small insects that have been gleaned off foliage. Insects are caught in straight flight also.
Just hanging around.
Bumblebee Bats roost in the hot upper chambers of caves in limestone hills, just about as far away from the entrance so that the small colony — up to 15 individuals — can fit without the bats being too close to each other.
The bats are small both in size and in number. The species was unknown prior to 1974. Their already restricted habitat has been highly affected by deforestation and unsustainable levels of teak logging. In 1982, the Royal Forest Department of the Thailand Government only found 160 of them living in 3 caves, despite extensive surveys. Bumblebee bats are now considered one of the twelve most endangered species on the planet.