A camel’s hump stores fat, not a tank of water. The camel can use that fat as an energy reserve when food is scarce. Camels conserve water through other physiological adaptations; although fat metabolism produces some water as a by-product, that does not mean a hump is a water container.
The hump is a fat reserve
Camels store much of their body fat in one or two humps, depending on the species. When an animal uses that reserve, the hump can become smaller or lean to one side. The Natural History Museum in London and San Diego Zoo both describe camel humps as fat stores rather than water stores. [1, 2]
Why concentrate fat in one place?
Concentrating fat in the hump leaves less insulating fat distributed under the skin across the rest of the body. That arrangement may help a camel release heat, although thermoregulation is only part of the explanation and should not be treated as a single proven reason for hump evolution. Fat also supplies energy when food is limited.
How camels manage water
Camels tolerate substantial water loss and reduce water use through several adaptations, including efficient kidneys and changes in body temperature over the day. Metabolizing fat releases some metabolic water, but the chemical process also requires oxygen and entails water loss. It is therefore misleading to describe the hump as a practical water bottle. [1]
For another desert science question, read why deserts can become cold at night and explore how wood frogs tolerate winter freezing.
Frequently asked questions
Do camels store water in their humps?
No. Humps store fat. Camels conserve water through other body systems and behaviors.
Can a camel make water from fat?
Fat metabolism produces some water as a by-product, but it does not turn the hump into a water reservoir.
Why does a camel’s hump shrink?
It can shrink as the camel uses stored fat for energy.
Sources and evidence
- Natural History Museum, London — How Do Camels Survive in Deserts? ↗
Explains hump fat, water conservation and other desert adaptations.
- San Diego Zoo Wildlife Alliance — Camel ↗
Confirms humps store fat and describes what happens as that reserve is used.
Sources consulted: 15 October 2026. Written with AI assistance and checked against the linked references; not independently reviewed by a subject specialist. Sources do not endorse this article. See our editorial policy.
Revision: Initial publication; metabolic water is distinguished from actual water storage, and the evolutionary explanation is presented cautiously.