Animals Wildlife 11 Smallest Animals of Their Kind From mini monkeys and diminutive deer to itty-bitty bats, these are some of the animal kingdom’s most minuscule members. By Melissa Breyer Melissa Breyer Twitter Editorial Director Hunter College F.I.T., State University of New York Cornell University Melissa Breyer is Treehugger’s editorial director. She is a sustainability expert and author whose work has been published by the New York Times and National Geographic, among others. Learn about our editorial process Updated November 6, 2020 Share Twitter Pinterest Email Portrait of a pygmy marmoset in natural habitat. Anolis01 / Getty Images Animals Wildlife Pets Animal Rights Endangered Species The world is filled with big things and the world is filled with little things. And while the big things boast magnitude and majesty, the little things ... well the little things boast an unwavering ability to elicit coos and squeals from us humans. As a species, we're hard-wired to fall for the cute and the little – an evolutionary guarantee that we'll take care of our babies. Which can make it hard to resist all the rest of the planet's smallest creatures as well. Consider the following. 1 of 11 1. Smallest Primate: Madame Berthe's Mouse Lemur credit: Melanie Dammhahn Named after the conservationist and primatologist Berthe Rakotosamimanana of Madagascar, Microcebus berthae is the smallest living primate known to us. Found mainly in western Madagascar, they ring in at a mere 3.6 inches in length on average and weigh just over an ounce. 2 of 11 2. Smallest Deer: Northern Pudú credit: Julie Larsen Maher/WCS There are two species of pudú, both hailing from South America – the Southern pudú, like the one pictured above, reaches a petite height of 14 to 18 inches at the shoulders, while its even more diminutive cousin, the Northern pudú, barely reaches 14 inches. Weighing in at the 7- to 13-pound range, they're about as heavy as a housecat! 3 of 11 3. Smallest Bird: Bee Hummingbird credit: charlesjsharp/Wikimedia The bee hummingbird of Cuba didn't get its name for nothing; at a wee two inches long and less than 2 grams in weight, it is the smallest bird in the world. Theoretically, 16 of them could be mailed first class using a single stamp. 4 of 11 4. Smallest Monkey: Pygmy Marmoset credit: Jakub Koziol Also known as known as the pocket monkey, little lion, and the dwarf monkey, the pygmy marmoset (Callithrix pygmaea) is considered the smallest monkey in the world. Weighing a lythe 4.20 ounces on average and measuring just over 5 inches, these South American forest monkeys could comfortably sleep in your hand. 5 of 11 5. Smallest Frog: Paedophryne amauensis credit: Wikimedia Commons At 7.7 millimeters long, the fly-size Paedophryne amauensis from Papua New Guinea is not only the smallest frog in the world, but also the smallest vertebrate on the planet! Scientist believe that P. amauensis evolved into its wee size to facilitate a diet of tiny invertebrates that larger predators pass over. 6 of 11 6. Smallest Mammal: Etruscan Shrew credit: Trebol-a While the Kitti's hog-nosed bat is the smallest mammal by skull size, sweet Suncus etruscus, the Etruscan shrew, is the smallest by mass. Weighing a teensy 1.8 grams and boasting a Lilliputian length of just an inch and a half, the shrewd shrew can nonetheless hunt prey the same size as itself. 7 of 11 7. Smallest Bat: Kitti's Hog-Nosed Bat credit: YouTube Craseonycteris thonglongyai is very special. Not only is this bat the smallest bat in the world, but also the smallest mammal, as measured by skull size, in existence. Also known as a bumblebee bat, Craseonycteris thonglongyai lives in Mayanmar and Thailand – on average, they reach only about an inch in length. 8 of 11 8. Smallest Seahorse: Denise's Pygmy Seahorse credit: timsimages At less than three-quarters of an inch in height, Hippocampus denise is like the tiniest miniature pony of the sea. Although so little in stature, these guys are big in skills; they are masters of camouflage and generally blend right in with the stems and polyps of their sea fan hosts. 9 of 11 9. Smallest Antelope: Royal Antelope credit: Mhx.andre Of course there's a world's smallest antelope, and naturally, it's royal. Neotragus pygmaeus hails from West Africa and was first described by famed Swedish zoologist Carl Linnaeus in 1758. At a vertically-challenged 10 inches in height and weighing a scant five to six pounds, the regal cutie wears the crown of smallest ungulate and ruminant as well. 10 of 11 10. Smallest Octopus: Octopus wolfi AndamanSE / Getty Images Well hello there teeny tiny octopus! The world's smallest octopus measures in at less than an inch, but that doesn't mean it's short of cunning – like any good octopus, it's known for its Houdini-like power of escape (take that, aquarium enthusiasts). Known since at least 1913, they can be found in waters up to 100 feet deep in the western Pacific. 11 of 11 11. Smallest Chameleon: Brookesia Micra credit: Frank Glaw This little lizard from Madagascar is the smallest known chameleon and, no surprise, is among the smallest of known reptiles. Adult males only reach lengths of one inch from nose to tail. Aside from its remarkable size, B. micra is notable for its big eyes; the scientists who discovered say that these little guys may represent the limit of miniaturization possible for a vertebrate with complex eyes. Until they find the next smallest-possible one, that is. And on the other end of the spectrum? 10 of the largest living things on the planet