Which animal can survive the longest without food? Some animals can go for months or even years without a meal. African lungfish survive prolonged droughts by entering a dormant state, olms can endure extended food shortages in caves, and certain soft ticks can survive years between blood meals. Scientists have even revived tardigrades after more than 30 years in frozen storage.
However, these extraordinary survival records describe very different biological conditions. Surviving while frozen is not the same as actively living without food, and going without food does not always mean going without water.
Here are 10 remarkable animals that can survive extended periods without eating, along with the science behind their unusual adaptations.
Quick Comparison: 10 Animals That Can Survive Without Food
| Animal | Reported Survival or Fasting Period | Survival Strategy |
|---|---|---|
| Tardigrade | 30.5 years in frozen cryptobiosis | Extremely low metabolic activity |
| Soft tick | Years; exceptional reports up to 18 years | Energy conservation between blood meals |
| Olm | Can survive years without feeding | Very low metabolism and limited activity |
| African lungfish | Months to years; reports up to 5 years | Aestivation inside a mucus cocoon |
| Galapagos giant tortoise | Up to approximately one year | Low metabolism and stored reserves |
| Emperor penguin | Up to 115 days in a scientific study | Stored body fat during breeding |
| Crocodile | Extended periods, potentially months | Low energy expenditure and fasting metabolism |
| Land snail | Extended seasonal dormancy | Aestivation and reduced water loss |
| Python | Long intervals between meals | Flexible digestive metabolism |
| Redback spider | Some adults survived more than 300 days in experiments | Metabolic adjustment during starvation |
Important: These figures are not directly comparable. Some involve natural fasting, others involve unusual laboratory conditions or biological dormancy. They are examples of survival adaptations, not a definitive ranking of which animal can endure starvation the longest.
1. Tardigrade: Surviving More Than 30 Years in Frozen Storage
Tardigrades, commonly called water bears, are microscopic animals famous for their ability to survive extreme environmental conditions.
When exposed to certain stressful conditions, some tardigrades enter a state called cryptobiosis. During this state, metabolic activity can become extremely low, allowing the animal to survive conditions that would kill many active organisms.
In a remarkable experiment reported in 2016, Japanese researchers revived Antarctic tardigrades recovered from moss that had been frozen for approximately 30.5 years.
Many animals that tolerate prolonged fasting are ectothermic, meaning they rely heavily on environmental heat rather than continuously generating enough metabolic heat to maintain a stable body temperature. Explore our 35 cold-blooded animal examples to understand how temperature regulation affects energy use.
Two animals and an egg were recovered, and some of the revived organisms subsequently reproduced.
Tardigrades can survive extraordinary environmental stress by entering a low-metabolism state.
Can tardigrades really survive 30 years without food?
The famous 30-year record involved animals preserved in frozen moss under controlled storage conditions. It does not mean an active tardigrade can walk around for 30 years without eating or drinking.
This distinction is important because cryptobiosis is fundamentally different from ordinary starvation.
Scientific evidence: National Institute of Polar Research, 2016.
2. Soft Ticks: Years Between Blood Meals
Soft ticks belong to the family Argasidae. Unlike insects, ticks are arachnids, a group that also includes spiders and mites.
Many soft ticks live in animal burrows, nests, caves or other protected environments. They feed on blood when suitable hosts become available.
Because hosts may be absent for long periods, some species have evolved remarkable starvation resistance.
A scientific review published in 2023 documented exceptional food-deprivation records for several soft tick species, including historical reports of up to 18 years in particular cases.
Ticks can conserve stored nutrients while waiting for their next host.
How do ticks survive so long without feeding?
Their adaptations include:
Low energy expenditure between meals.
Effective use of stored nutrients.
Reduced water loss.
Protected resting habitats.
The ability to wait for infrequent feeding opportunities.
These extreme observations do not apply to every tick species or life stage.
Some soft ticks are also important disease vectors, making their ability to survive between blood meals relevant to public health.
3. Olm: A Cave Salamander That Can Endure Years Without Food
The olm (Proteus anguinus) is a cave-dwelling amphibian found in parts of southeastern Europe.
It lives in underground aquatic habitats where food supplies can be scarce and unpredictable.
Olms have elongated pale bodies, reduced eyes and specialized sensory abilities that help them navigate in darkness.
Unlike many surface-dwelling amphibians, they have an exceptionally low metabolic rate and can remain relatively inactive for long periods.
The olm is adapted to dark, food-limited underground aquatic environments.
Can an olm survive 10 years without eating?
The Zoological Society of London reports that olms can survive up to 10 years without food. Experimental research also confirms their remarkable physiological adaptation to prolonged starvation.
However, the exact duration an individual survives depends on its condition and environment. The often-repeated 10-year figure should not be treated as a guaranteed survival period for every olm.
Why can it survive? Its low metabolic rate and ability to conserve energy are adaptations to an environment where prey is often scarce.
4. African Lungfish: Surviving Years of Drought
African lungfish are among the most remarkable vertebrates capable of surviving prolonged environmental drought.
Some African lungfish species, including Protopterus annectens, can enter a dormant state called aestivation.
When seasonal waters disappear, lungfish can burrow into mud and produce a protective mucus cocoon.
Inside this structure, their metabolism decreases dramatically. They continue to breathe air while surviving on internal energy reserves.
African lungfish are adapted to seasonal drought and can enter prolonged dormancy.
How long can lungfish survive without food?
Scientific reviews describe African lungfish surviving months or years during aestivation, with periods of up to approximately five years reported.
These are exceptional conditions. Lungfish normally feed when active and when their aquatic habitat provides suitable food.
Why can they survive? Their ability to drastically reduce energy consumption allows stored reserves to last much longer than during normal activity.
5. Galapagos Giant Tortoise: Surviving With Stored Reserves
Galapagos giant tortoises are among the largest living terrestrial tortoises. They are herbivores that feed on grasses, leaves, cactus pads, fruits and other vegetation.
Their relatively low metabolism and ability to store substantial reserves help them survive when food and water are difficult to obtain.
The San Diego Zoo reports that Galapagos giant tortoises may survive for up to approximately one year without eating or drinking under exceptional conditions.
Galapagos giant tortoises have physiological adaptations that help them endure periods of scarcity.
Does this mean giant tortoises normally go a year without food?
No. The reported endurance describes an unusual survival capability, not normal feeding behavior.
Under ordinary conditions, giant tortoises feed regularly. Long-term deprivation is not a recommended practice for captive animals.
Their impressive fasting tolerance reflects adaptations to environments where food and freshwater availability can change seasonally.
6. Emperor Penguin: Fasting Through the Antarctic Winter
The emperor penguin (Aptenodytes forsteri) provides one of the most remarkable examples of prolonged fasting among birds.
Male emperor penguins incubate their eggs during the Antarctic winter while females return to the ocean to feed.
Throughout much of this breeding period, the male remains away from marine feeding grounds and relies on stored fat reserves.
A physiological study published in 1982 documented breeding-related fasts lasting up to approximately 115 days.
How do emperor penguins survive without eating?
Before breeding, emperor penguins accumulate substantial energy reserves.
During incubation, they reduce energy expenditure and carefully use stored fat to sustain themselves while protecting the egg.
They also conserve heat by gathering closely together in groups during extreme Antarctic weather.
Why is this example special? Unlike the frozen tardigrade or aestivating lungfish, the emperor penguin remains physiologically active while enduring a naturally prolonged fast.
7. Crocodile: An Energy-Efficient Predator
Crocodiles can survive extended intervals between meals because their energy requirements differ from those of similarly sized warm-blooded mammals.
As ectothermic reptiles, crocodiles rely heavily on external heat sources to regulate body temperature. They do not continuously spend large amounts of energy maintaining a constant internal temperature.
They can also remain relatively inactive between feeding opportunities.
Crocodilians can conserve energy during periods when prey is unavailable.
Can crocodiles really survive three years without food?
The claim that crocodiles routinely survive three years without eating is too broad to be scientifically reliable.
Starvation tolerance depends on species, age, body reserves, temperature and activity levels.
Research on estuarine crocodiles shows that fasting individuals can reduce metabolic demands and use stored fat, but prolonged starvation eventually causes physiological deterioration.
It is more accurate to say that crocodiles are highly adapted to irregular feeding opportunities than to assign every crocodile a fixed multi-year starvation record.
8. Land Snail: Surviving Dry Seasons Through Aestivation
Many terrestrial snails depend on moisture for normal activity. When conditions become extremely dry or hot, some species enter aestivation.
During this dormant period, a snail withdraws into its shell and may form a temporary protective seal called an epiphragm.
The seal helps reduce moisture loss while the snail remains inactive.
Some land snails become dormant during hot or dry periods to conserve moisture and energy.
How long can a snail survive without food?
The duration varies considerably between species and environmental conditions.
For example, the U.S. Fish and Wildlife Service describes how the Morro shoulderband snail can spend much of the dry portion of the year in aestivation.
This provides a well-documented example of prolonged seasonal dormancy, but it does not justify claiming that every snail can survive three years without food or water.
9. Python: Long Intervals Between Large Meals
Pythons use a different feeding strategy from animals that eat small amounts throughout the day.
They can consume relatively large prey and spend considerable periods digesting their meals.
After feeding, the python's digestive system undergoes remarkable physiological changes.
Research in the Journal of Experimental Biology found that the small intestine of a Burmese python can increase substantially in size after feeding, with changes that are reversible as digestion progresses.
Pythons are adapted to eating large meals separated by extended fasting periods.
How long can a python go without eating?
There is no single reliable maximum that applies to all pythons. Meal intervals vary with species, body size, temperature, age and health.
Claims that pythons universally survive two or three years without food should not be treated as established facts.
The important scientific finding is that pythons can adjust their digestive activity and metabolism to accommodate infrequent meals.
10. Redback Spider: An Experimentally Documented Long Fast
Some spiders can withstand surprisingly long periods without feeding.
A study on Australian redback spiders (Latrodectus hasselti) investigated how temperature affected survival during food deprivation.
Under experimental conditions, some adult spiders survived more than 300 days without food.
The researchers found that lower temperatures generally increased survival time, while warmer conditions reduced it.
Starved spiders also became less active and showed progressive physiological deterioration.
Does this mean spiders do not need food?
No. The experiment measured survival under food deprivation, not healthy long-term maintenance.
Spiders normally require suitable prey and environmental conditions. The exact fasting tolerance varies substantially between species.
This is also different from the temporary reduction in feeding that some tarantulas experience before molting.
How Do Animals Survive So Long Without Eating?
Animals have evolved several different biological mechanisms for coping with food shortages.
1. Reducing metabolic activity
Some organisms dramatically reduce their energy requirements during dormancy, allowing stored resources to last longer.
2. Storing energy before food becomes scarce
Emperor penguins accumulate body fat before prolonged breeding fasts. Other animals also depend on internal energy reserves during periods without food.
3. Lowering activity levels
Animals that remain inactive generally expend less energy than those continuously moving, hunting or maintaining high activity levels.
4. Entering aestivation or cryptobiosis
Aestivation and cryptobiosis are distinct biological responses, but both can help certain organisms survive unfavorable environmental conditions.
5. Adapting digestion to infrequent meals
Some predators, including pythons, can alter digestive activity after feeding and during prolonged intervals between meals.
Fasting vs Starvation vs Dormancy: What's the Difference?
| Term | Meaning | Example |
|---|---|---|
| Natural fasting | A temporary period without feeding that occurs as part of normal behavior. | Male emperor penguin during breeding |
| Starvation | Prolonged insufficient food intake that progressively threatens normal physiological function. | Animals in food-deprivation studies |
| Aestivation | Dormancy associated with adverse conditions such as drought or heat. | African lungfish |
| Cryptobiosis | A state in which metabolic processes become extremely low. | Tardigrade |
These distinctions explain why the question "Which animal can survive the longest without food?" does not have one universally applicable answer.
Which Animal Can Survive the Longest Without Food and Water?
The answer depends on whether dormant, frozen or actively living animals are included.
Tardigrades have an extraordinary experimental record of surviving more than 30 years in frozen storage. African lungfish can survive years of prolonged aestivation. Some soft ticks also survive exceptionally long intervals between blood meals.
But being frozen, living inside a drought-resistant cocoon, and remaining physiologically active are fundamentally different conditions.
Even when an animal is not drinking or eating, it may retain water, conserve moisture, use internal energy stores or obtain resources through processes that differ from those of an active animal.
Frequently Asked Questions
What animal can go the longest without eating?
Tardigrades have survived more than 30 years in frozen cryptobiosis, but this is not normal active fasting. African lungfish and certain soft ticks are among the remarkable examples of animals capable of enduring food shortages for years under specific conditions.
Can an animal survive 10 years without food?
Some exceptional reports involve many years of food deprivation or dormancy. Olms are described as capable of surviving up to 10 years without feeding, while selected soft tick species have even longer historical records. These are not typical survival periods for most animals.
What animal can survive without food for a year?
Galapagos giant tortoises are reported by the San Diego Zoo to survive up to approximately one year without food or water under exceptional conditions. Some other organisms can withstand long periods of food deprivation depending on their environment.
How long can a crocodile survive without eating?
Crocodiles can endure extended fasting thanks to their low energy requirements, but there is no single reliable duration for all species and circumstances. Body condition, temperature and age significantly affect survival.
Can snakes survive months without food?
Some snakes can go for prolonged intervals between meals. Their fasting tolerance depends on species, environmental temperature, body condition and the size of previous meals.
Do animals need water even when they are not eating?
Water requirements and food requirements are different. Some animals conserve water during dormancy or survive using stored reserves, but these adaptations do not apply universally.
Animals That Eat the Most vs Animals That Survive Without Food
Animal feeding strategies vary enormously. A blue whale consumes vast quantities of krill, while a lungfish can survive prolonged droughts by drastically reducing its metabolism.
Some animals feed frequently because of high energy demands, while others are adapted to unpredictable feeding opportunities.
For the opposite perspective, explore our 10 Animals That Eat the Most guide, which compares blue whales, hummingbirds, sea otters, pandas and other remarkable eaters.
Conclusion
From tardigrades surviving decades in frozen storage to lungfish enduring years of drought, animals have evolved extraordinary ways to withstand food shortages.
The most remarkable feature is not simply how long an animal can go without eating, but how its physiology changes to survive difficult conditions.
Understanding those adaptations reveals the diversity of energy use, metabolism and survival strategies across the animal kingdom.
Scientific Sources and Further Reading
National Institute of Polar Research — Tardigrades Revived After 30 Years
Journal of Experimental Biology — Python Digestive Adaptations
New Zealand Journal of Zoology — Starvation in Redback Spiders
Reviewed October 27, 2026. Extreme survival records depend on species, environmental conditions and experimental methods. These observations should not be used to justify withholding food or water from captive animals.
