Meet the World’s Smallest Mammals

All five of these smallest mammals in the world clock in at about 1 ounce or smaller.

Yes, all mammals are warm-blooded, but not all of them can be as big or ferocious as a lion.

In fact, all five of these smallest mammals in the world clock in at about 1 ounce or smaller, and none of them are longer than an average human’s index finger.

Despite their small stature, though, these tiny critters make up a very rich and varied part of our ecosystem. Here’s a look at these little contributors to our big, abundant world.

5. Madame Berthe’s Mouse Lemur

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Weight: 1.2 ounces

Length: 3.6 inches

The Madame Berthe’s mouse lemur is the smallest lemur in the world. Like all lemur species, this one is indigenous to Madagascar but can be found in nearby areas as well.

Typically found in dry, deciduous forests, the Madame Berthe’s mouse lemur has a dwindling population as a result of a seven-month dry season, temperature fluctuations and food scarcity. As such, it’s considered an endangered species.

If you’re hoping to spot one of these tiny mammals in the wilderness, make sure to do it at night, as it’s a nocturnal creature. It’s also a fairly solitary mammal, except for when it’s sleeping, which it does in groups.

4. Baluchistan Pygmy Jerboa

Weight: 0.13 ounces

Length: 2 inches

Jerboas are desert rodents, and the Baluchistan pygmy jerboa (or dwarf three-toed jerboa) is the smallest of its kind. It can be found in the gravel flats and sand dunes of Pakistan.

Despite their miniature size, they can move quite quickly through their dry habitats, hopping long distances by balancing on their tails. They live off seeds and succulent leaves and find shelter by burrowing in holes beneath desert bushes.

3. Etruscan Shrew

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Weight: 0.046 to 0.088 ounces

Length: 1.5 inches

Smaller than the size of a human thumb, Etruscan shrews live in the Mediterranean lowlands from Portugal to the Middle East, and some have also been found in Africa.

They have short, grayish-brown fur and have distinct smaller hind limbs. They spend their days being quite active in search of food — typically small insects such as crickets, ants and mealworms.

Fun fact: Research shows that they are likely monogamous, but it’s not known for sure.

2. Kitti’s Hog-Nosed Bat

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Weight: 0.074 ounces

Length: 1 inch

The Kitti’s Hog-Nosed Bat is the smallest bat in the world, and its name comes from the cute signature pig-like nose that it touts.

Its geographic range includes Thailand and Myanmar, where it lives in colonies as large as 100 bats amidst the limestone caves situated along these countries’ prominent rivers.

These bats are particularly active at dawn and dusk, and they primarily live off of flies. Threatened by habitat loss, this is another mammal that’s sadly on the brink of extinction.

1. Long-Tailed Planigale

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Weight: <0.004 ounces

Length: 0.12 inches

The smallest marsupial on the planet, the long-tailed planigale hails from northern Australia.

They’re so tiny that they’re difficult to spot in the northern grasslands that they call home. While all planigales have flattened heads, the long-tailed ones resemble mice. And like mice, they feast on small creatures that they forage for at night.

For more of the world’s smallest creatures, check out “35 Smallest Animals in the World.”