Answer: Etruscan Shrew

If you’re looking for a scale-tipping beast, you won’t find it in today’s trivia. The world’s smallest mammal, the Etruscan shrew, weighs a scant 1.8 grams (or, for reference, around the same as three regular paper clips). It is found along the coasts of the Mediterranean Sea, as well as in parts of the Middle East and Southern Asia.

Not only is this tiny member of the shrew family a curiosity thanks to its size, but also thanks to its habits. The shrew’s metabolism is so active (think of it like a tiny, furry hummingbird) that it spends a significant portion of each day hunting simply to stay alive. In between short cat-naps of thirty minutes or less, the Etruscan shrew is a highly efficient hunter stalking insects, rodents, lizards, amphibians, and other small prey in order to consume approximately double its own body weight to stay alive.

Because of the enormous demands of their rapid metabolism, in cooler weather they go into a state of temporary hibernation. When they emerge from hibernation, they raise their body temperature by vibrating in place at a frequency of roughly 60 vibrations a second (among the highest rate of “shivering” ever observed in mammals); by comparison, the incredibly rapid shake of a rattlesnake’s tail is only around 50 vibrations a second.

Before we leave the subject of the world’s tiniest mammals, let’s give a nod to the next in line: the bumblebee bat. When classified by skull size and body length, the bumblebee bat is considered the smallest mammal around, but when classified by total mass (a far more practical measure), it outclasses the Etruscan shrew and loses the title of tiniest mammal. Even combined, however, they still weigh next to nothing. If we could get them to combine their powers into a shrew-carrying-bat tag team, then we’d end up with a dynamic duo weighing less than a nickel.