What is the smallest mammal in the world?

The smallest mammal in the world by weight is the bumblebee bat (Craseonycteris thonglongyai), also known as Kitti’s hog-nosed bat. It weighs about 2 grams (0.07 ounces) and measures approximately 2.9 to 3.3 centimetres (1.1 to 1.3 inches) in length. Found in limestone caves in Thailand and Myanmar, this tiny bat feeds on insects and is active during twilight. Its small size and distinctive pig-like snout make it a unique species. Despite its diminutive stature, the bumblebee bat is an important part of its ecosystem, helping control insect populations.