The Bumblebee Bat (Craseonycteris thonglongyai).

The world's smallest bat. Arguably the world's smallest mammal. 2 grams. About the size of a large bumblebee.

It lives in limestone caves along rivers in Thailand and Myanmar, leaves its roost for just 30 minutes each evening and 20 minutes at dawn to hunt insects. The rest of the time it stays completely still.

Unknown to science until 1974. Named after the Thai zoologist who discovered it, Kitti Thonglongya, who died before the species was formally described.

The entire estimated world population: around 10,000 individuals.