The world's smallest mammal is the bumblebee bat (Craseonycteris thonglongyai), which is native to parts of Thailand and Myanmar. These tiny bats have a wingspan of about 5.7 to 5.9 inches (14.5 to 15 centimeters) and weigh only around 2 grams. They are known for their diminutive size and are often considered one of the world's most lightweight mammals. Bumblebee bats primarily feed on small insects and are known for their unique appearance and behaviors, making them a subject of interest among mammalogists and wildlife enthusiasts.