Why Japan's Snow Monkeys Sit in Hot Springs
Created by Brando Oxley · 23 Aug 2026
Key Vocabulary
a common name for the Japanese macaque
A snow monkey sat near the warm water.
a place where naturally warm water comes from the ground
The monkeys went into the hot spring.
to wash or sit in water
The monkeys bathe more often in winter.
a feeling or body reaction caused by difficulty or pressure
Cold weather can add stress to the body.
the warmth made and kept by a person's or animal's body
The hot water helps the monkeys keep body heat.
Article
In the mountains of Nagano, Japan, some Japanese macaques sit in a hot spring while snow covers the ground. These animals are often called snow monkeys. They have used the warm water for many years. [1]
A hot spring is a place where warm water comes naturally from the ground. The monkeys at Jigokudani first started using one in the 1960s. Later, the park made a hot spring only for the monkeys. [1]
Scientists wanted to know why the monkeys bathe. In a 2018 study, they watched 12 adult female monkeys in spring and winter. They also checked signs of stress in the monkeys' waste. [1][2]
The snow monkeys bathed more often in winter, especially during colder weeks. The hot water helped them keep body heat, so their bodies did not need to work as hard to stay warm. [1]
The researchers also found lower stress levels when the monkeys used the hot spring. Monkeys with a higher place in the group could bathe more, although they also had more fights with other monkeys. [1][2]
For people watching from the snow, the bath can look almost human. For the monkeys, it is a useful winter habit: warm water gives them a quiet way to save body heat when the air becomes very cold.
Discussion Questions
- What do you find interesting about the snow monkey's winter habit?
- Where do people in your country go to bathe in warm water?
- What helps you keep body heat on a very cold day?
- What kinds of weather cause stress for animals where you live?
- What other animal behavior would you like scientists to study?
References
- Kyoto University, "Spa therapy helps Japan’s snow monkeys cope with the cold." Source
- Primates, "Beneficial effect of hot spring bathing on stress levels in Japanese macaques." Source
- American Journal of Primatology, "Hot spring bathing in Japanese macaques (Macaca fuscata): implications for behavioral thermoregulation." Source
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