Koala sleeps for almost 22 hours a day. It remains awakened for only 2 hours per day. It is found in coastal areas of Australia and Tasmania. A healthy female koala can produce one young each year for about 12 years. The koala lives almost entirely on eucalypt leaves.

Based on the number of toes, they are placed in either of the two mammalian families, viz. Bradipodidae or Megalonychidae. The most outstanding feature of Sloths is their slow movement and this can be attributed to the poor circulatory system and drowsy reflexes. Another important characteristic is their restive nature as in 24 hours; they sleep for about 19 hours and remain active only for 5 hours. They spend most part of their lives in hanging positions on tree branches and rarely come on the ground, where they are not safe from enemies. On trees, the presence of algae and their camouflage save them from enemies. From these algae, certain insects get their food. Sloths can perform almost every vital activity, viz. eating, sleeping, mating and even giving birth to their young ones while hanging from the tree. There are two types of Sloths. One is with two toes and is known as Unau and the other is with three toes and is known as Ai or maned sloth. Apparently both resemble each other but the difference is in their skeleton i.e. the Ai has nine cervical vertebrae and either twenty-eight or thirty ribs, whereas Unau has six or seven cervical vertebrae and either forty-six or forty-eight ribs. They have 18 teeth which help in the grinding of leaves and the rough tongue pushes them back. They do not eat much because of slow mastication and digestion. Their tail is short, head is round, the immoveable eyes are round with short sightedness and their face lacks expression. The horny lips on small mouth are for mastication and their snout has two nostrils. In spite of all these facts, the most interesting thing is that with all their sluggishness, they can swim with the help of their forefeet at the need of the hour. Their speed is approximately 550 yards an hour. So it can be said that they are slow on lands, but not in water.

Armadillo sleeps for 19 hours a day. Armadillo is a beautiful looking animal with leather armour shell. Mostly these animals are found in American stats of Texas, South Carolina and Florida.

Opossum also sleeps for the same hours as Armadillo sleeps. The hours are 19 which means that it remains awakened for only 5 hours a day. Its habitat is the areas of Canada.

Lemur sleeps for almost 16 hours a day. Lemur is a good looking animal which is found in Madagascar. It behaves like monkies and they live mostly on trees. They are mostly omnivores and eat meat or vegetables or fruits.

Hamster is one of the sleepiest animals which rests at 6th position and it sleeps for about 14 hours a day. The habitat of Hamster is all the parts of the world. Hamster are rodents like mouse which mostly live under the earth.

Squirel is found in almost all parts of the world and it sleeps for 14 hours a day. Squirel belongs to rodent family.

Cat is the most popular pet in the world and it is also one of the most sleepiest animal in the world as it sleeps for 13 hours a day. Cat is a carnivore as it eats flesh mostly.

Pigs are omnivores and they can be found on almost all parts of the world. They sleep for almost 13 hours a day like cats.

Spiny Anteater is popular for eating ants. They live in New Guinea and Australia. They are also known as Echidna. They sleep for about 12 hours a day that is why they are considered as the most sleepiest animals of the world.