How Long Do Animals Live?

Animal lifespans range from roughly 24 hours for the adult mayfly to over 400 years for the Greenland shark — and one species, the immortal jellyfish (Turritopsis dohrnii), can biologically reverse its aging process and theoretically live indefinitely. Humans at around 79 years land squarely in the middle of the animal kingdom's spectrum.

The Short End: Animals That Live for Hours or Days

The adult mayfly lives for just one day. Its entire adult existence — mating, reproducing, dying — fits inside 24 hours. Mayflies spend most of their lives as aquatic nymphs, sometimes for 2-3 years, but once they emerge with wings the clock runs out almost immediately.

Worker bees live about 6 weeks during summer months, drones slightly less. The queen bee can live 3-5 years by comparison — the colony's investment in one long-lived reproducer instead of many short-lived workers. Houseflies clock in at 28 days on average. Gastrotrichs (microscopic aquatic animals) have a full lifecycle of just 3 days.

The Middle Range: Familiar Animals

Most of the animals humans interact with daily cluster in a recognizable range:

• Mouse: 1-3 years
• Rabbit: 8-12 years
• Dog: 10-13 years (varies enormously by breed)
• Cat: 12-18 years
• Horse: 25-30 years
• Crow: 7-8 years wild, up to 30 in captivity
• Chimpanzee: 40-60 years

Body size correlates loosely with lifespan — larger animals tend to live longer — but the rule breaks down constantly. Bats are tiny and live 20-40 years. Naked mole rats weigh 35 grams and routinely live past 30 years, far outliving other rodents of similar size.

The Long End: Centuries-Old Animals

The Greenland shark reaches sexual maturity at about 150 years of age and has an estimated maximum lifespan of 500 years. One specimen was dated at approximately 392 years old — meaning it was born around 1620, before Newton published his laws of motion. They move at less than 1 mph and live in near-freezing Arctic water, which may be part of their longevity secret.

Ocean quahog clams regularly exceed 200 years. The oldest confirmed individual, nicknamed Ming, was 507 years old when scientists accidentally killed it by trying to measure its age. Ocean temperatures in its habitat average 5°C — cold water dramatically slows metabolic processes.

Giant tortoises are the most famous long-lived land animals. Jonathan the Seychelles giant tortoise, born around 1832, is still alive as of 2026 — making him approximately 194 years old. He was already 50 when Queen Victoria was crowned.

The Greenland shark alive today swam through water when Shakespeare was still writing plays. Time works differently for animals we share a planet with.

The Outlier: Biological Immortality

The immortal jellyfish (Turritopsis dohrnii) can, under stress, revert its cells from their mature adult state back to the polyp stage — essentially rewinding its biological age. It can cycle through this process indefinitely, making it theoretically immortal. The practical limitation is predation and disease, not aging. In a predator-free environment, one of these jellyfish might simply never die.

Hydra, a tiny freshwater animal, shows similarly negligible aging — their mortality rate doesn't increase with age the way it does in virtually every other organism studied.

Why Does Lifespan Vary So Much?

Evolutionary theory offers the clearest explanation: animals evolve longer lifespans when mortality risks are low and shorter ones when predation is high. A mouse that survives a year is already beating the odds, so evolution never invested in cellular repair mechanisms that would let it live 20 years. A Greenland shark in freezing deep water has almost no predators and enormous body mass — so it paid off to build for longevity.

The Food Chain simulator shows how these predator-prey relationships shape what lives long and what lives fast. The Evolution Sim lets you run these pressures yourself and watch traits like lifespan-versus-reproduction emerge from selection pressure. For a broader look at the diversity behind these numbers, Animal Quiz tests how well you know the creatures sharing Earth with us.

For more context on the sheer number of species behind this variety, the how many species are on Earth post covers the estimates and what we still don't know. And for speed comparisons that complement lifespan, how fast is the fastest animal puts cheetahs, falcons, and sailfish in perspective.