Smallest

Animals come in all shapes and sizes, and some small animals can be really small.

Some invertebrates not even visible to the human eye: some mites are known to measure only 200μm (0.0002mm) in length, a parasitic wasp can be as small as 139μm (0.0001mm) long, and there’s a tiny beetle which is less than 1 mm long. Given the minute size of these animals, who knows what we have yet to discover.

Here is a selection of the smallest vertebrate animals on earth. Some people think the smallest animals are the shortest in height, or length, or the lightest. Which ever way you measure them these really are some amazing little animals.

1- Pygmy Marmoset

The Pygmy Marmoset or Dwarf Monkey (Cebuella pygmaea) is the world’s smallest monkey. It is native to the rainforest canopies of Brazil, Columbia, Ecuador, Peru and Bolivia. It is one of the smallest primates, and the smallest true monkey, with its body length ranging from 14 to 16cm (excluding the 15 to 20cm tail). Males weigh around 140g, and females only 120g. They weigh only 15g at the time of birth. The lifespan of these monkeys is 11 to 16 years. They usually give birth to twins.

2- Madame Berthe's Mouse Lemur

The smallest primate is the Madame Berthe's Mouse Lemur (Microcebus berthae), found in Madagascar, with an average body length of 92 mm and weight of around 30g. It is found in the Kirindy Mitea National Park in Western Madagascar.

3- Pygmy Rabbit

The Pygmy Rabbit (Brachylagus idahoensis) is the smallest rabbit. It is found in North America. The adult pygmy rabbit weighs about 400 g having a body length of 24cm to 29cm; females are slightly larger than males. They are generally limited to areas on deep soils with tall, dense sagebrush which they use for cover and food. Extensive, well-used runways interlace sage thickets and provide travel and escape routes from predators such as weasels.

4- Paedocypris

The Paedocypris (Paedocypris) is the smallest fish, at only 7.9mm in length. This is also considered as the smallest vertebrate. It is found in the peat swamp forests of Indonesia’s Sumatra Island and can survive extreme drought in part due to their small size (just 7.9 mm long at maturity). Much of their habitat is acid water, with pH as low as 2.9. The members of the genus are thought to be highly endangered.

5- Gold Frog

The smallest frog in the Southern Hemisphere is the Gold or Brazilian Frog (Psyllophryne Didactyla). Adult Gold Frogs measure grow to only 9.8 millimetres in body length (with legs drawn in). Equally small is the smallest frog in the Northern Hemisphere, only recently discovered (1996) in Monte Iberia, Cuba. It doesn't have a common name yet, but its scientific name is Eleutherodactylus iberia.

6- Slender Blind Snakes

The Slender Blind Snakes or Thread Snakes (Leptotyphlopidae) are a family of snakes thought to be the world’s smallest snakes at about 11cm in length. They are found in North and South America, Africa, and Asia. There are 87 different species of these snakes. They are adapted to burrowing, feeding on ants and termites. Their diet consists mostly of termites or ants, their larvae and pupae. Most species suck out the contents of insect bodies and discard the skin.

7- Kitti's Hog-nosed Bat 

The Kitti's Hog-nosed Bat  (Craseonycteris thonglongyai), or Bumblebee Bat from Thailand and Burma is the smallest bat, at 30–40mm in length and 1.5 to 2g in weight. It is about the same size as a bumblebee and has a distinctive pig-like snout, hence its different common names. It lives in limestone caves along rivers. Colonies range greatly in size, with an average of 100 individuals per cave. The bat feeds during short activity periods in the evening and dawn, foraging around nearby forest areas for insects. Females give birth annually to a single offspring. Although the bat's status in Burma is not well-known, the Thai population is restricted to a single province and may be at risk for extinction. Its potential threats are primarily anthropogenic, and include habitat degradation and the disturbance of roosting sites.

8- Etruscan shrew

The Etruscan shrew (Suncus etruscus), also known as the Etruscan Pygmy Shrew or the White-toothed Pygmy Shrew weighs only 1.2 to 2.7g so could be considered the world’s smallest mammal, although it is slightly longer than the Bumblebee Bat at 36 to 53mm from its head to the base of the tail. The Etruscan Shrew inhabits forests and brush areas between Southern Asia and Southern Europe. This shrew has a lifespan of 15 months. A forager, it subsists largely upon insects. It’s heart beats 14 times per second. The shrew's brain is the largest in ratio to its body weight of all animals, larger than even a human's.

9- Bee Hummingbird

The Bee Hummingbird (Mellisuga helenae) is the smallest bird and the smallest warm-blooded vertebrate.. It is also known as Cuban bee as it is found mostly in Cuba. It measures 5.7cm in length and 1.8g in weight. The Bee Hummingbird is said to eat half its total body mass and drink eight times its total body mass each day. We cannot see its wings while flying as it flaps its wings 90 times per second. The heartbeat of this bird is 1,260 times. The size of its nest measures 2cm wide and 3cm deep. Its eggs are smaller than coffee grounds.

10- Speckled Padloper Tortoise

The world's smallest turtle is the Speckled Padloper Tortoise (Homopus signatus) from South Africa. The males measure 6–8cm, while females measure up to almost 10cm.