Long-nosed monkeys are found only on Kalimantan Island in southeastern Asia, formerly known as Borneo, now in the north of Brunei and Sarawak, Malaysia, and in the south of Sabah, part of Indonesia. The climate here is hot, the land is barren, and mosquitoes and sandflies often harass, the living environment is not ideal. Long-nosed monkeys are endemic to Kalimantan in Southeast Asia. Their noses are surprisingly large, with male monkeys getting bigger and bigger with age, and eventually forming large red noses like eggplants. When they are excited, their big noses will stand up or shake up and down, looking ridiculous. The female's nose is more normal. But their IQ is very high. Long nosed monkeys like to live in groups, often 10.30 in a group, with a range of less than 2 square kilometers. Good at swimming, often in the river while looking for food, while playing, but sometimes they can still stay motionless for several hours. Long-nosed monkeys (Nasalis larvatus) are the only species of monkeys belonging to the family Monkeyidae. They are the heaviest monkeys in the world. Long-nosed monkeys are characterized by their large, long noses. Their use is not very clear. It may be the result of sexual selection. Male monkeys are much bigger than female monkeys, usually 72 centimeters long, 78 centimeters long tail and 24 kilograms heavy. The female monkey is only 60 centimeters long and weighs 12 kilograms. Long-nosed monkeys have large abdomen, and their digestive system is divided into several parts, which helps them digest leaves. Hands and feet have five fingers, toes, flat nails, can stand upright. Male Rhinopithecus can weigh up to 25 kilograms, and female Rhinopithecus is less than half of male rhinopithecus. It is said that the long nosed monkey is the heaviest monkey in the world. The biggest difference between long-nosed monkeys and other monkeys is that the nose of adult males grows larger and larger with age, and eventually reaches 7.8 cm in length. Because of its red color, it looks like an eggplant-shaped red balloon hanging on its face from afar. Because this big nose hangs in front of the mouth and sways, when eating, it has to be tilted to one side first. In addition, the male of the Rhinopithecus monkey also has a distinctive, bulging belly, so that people who are not familiar with the characteristics of the Rhinopithecus monkey often mistake it for a female about to give birth. By contrast, the female of the long nosed monkey is very small. It is less than half the size of the male. It weighs only 11 kilograms. It has neither a huge hanging nose nor a particularly bulging belly. It is only covered with bright red body hair all over its body, showing its unique charm.