Lemurs are a group of primates that live on Madagascar and the Comoros Islands. The five living families of lemur are the Lemuridae (true lemurs), the Lepilemuridae (sportive or weasel lemurs), the Indriidae (indris, avahis and sifakas), the Daubentonia (aye-ayes) and the Cheirogaleidae (mouse and dwarf lemurs).  Lemurs, lorises and bushbabies are members of the suborder of wet-nosed primates, or Strepsirrhini.  These primates have dog-like snouts.  Apes (including humans), monkeys and tarsiers are dry-nosed primates, or Haplorhini.

The world's smallest primate is a lemur - Madame Berthe's Mouse Lemur. It weighs, on average, 1 ounce (30 grams) and is only about 3.6 inches (9 centimeters) long.

Lemurs have soft, thick fur that is often red, brown, gray or black. They are often multicolored and may have large areas of white fur or white undersides.

A lemur has a thick, furry tail.  It has big eyes and fur on its ears. Its head resembles a fox's head.

Lemurs live in trees.  They walk along branches on all fours. They  have ridges on their palms and the soles of their feet, and their thumbs and big toes are angled away from their other fingers and toes.  These adaptations help them hold on to branches.  They  use their tails for balance. Lemurs are strong jumpers and leap from tree to tree. Their tails help them to balance and maneuver during leaps. Some lemurs have very long hind legs that also help with jumping.

Some species, such as the ring-tailed lemur, spend a great deal of time on the ground.

Lemurs eat fruit and leaves. Some also eat insects.

Most lemurs are diurnal, but dwarf lemurs and mouse lemurs are active at night.

Many lemurs live in social groups, which can contain as much as 20 individuals. Each group has its own territory. In lemur society, females are dominant.

Lemurs communicate by scent, by vocalizations and by gesture. They bond with another by grooming. Many lemurs have long, claw-like nails known as "toilet claws", which are used for grooming, on the second toe of each foot.

Almost all species of lemur are threatened or endangered because of hunting, habitat destruction and the pet trade. Climate change, which has been causing increasing drought in Madagascar, is also threatening the existence of lemurs.

Scientists think that the ancestors of lemurs traveled from Africa to Madagascar on rafts of floating vegetation.  Africa and Madagascar used to be connected, forming part of the ancient supercontinent of Gondwana, but they had already separated by the time lemurs arrived in Madagascar.  The continent and the island have drifted further apart since then. Consequently, lemurs developed in isolation, evolving into many unique species.