Iguana Facts (2026): Lifespan, Size and Surprising Anatomy

What Is an Iguana?

An iguana is a lizard in the family Iguanidae. Like all lizards, iguanas are reptiles: cold-blooded vertebrates with scaly skin that lay eggs. The word "iguana" comes from iwana, a word in the language of the Taíno people of the Caribbean. Most of the time, "iguana" refers to the green iguana, Iguana iguana, but the family also includes rock iguanas, spiny-tailed iguanas, the Galápagos marine and land iguanas, Fiji iguanas and the desert iguana. See types of iguanas.

Iguana Facts at a Glance

Fact	Green iguana
Animal type	Reptile (lizard)
Scientific name	Iguana iguana
Size	Commonly 4–6 ft including tail
Weight	Males up to about 17 lb
Lifespan	Up to about 10 years wild; 19+ in captivity
Diet	Herbivore
Eggs	About 14–76 per clutch
Native range	Central and South America, Caribbean

Iguana Body Facts

• Third eye: iguanas have a parietal eye, a small light-sensitive spot on top of the head that helps them detect light and movement from above. See iguana third eye.
• Excellent vision: iguanas see color and ultraviolet light and can spot movement at a distance.
• Visible ear openings: iguanas have an eardrum just behind the eye, with a large round scale, the subtympanic shield, below it on green iguanas.
• Replaceable teeth: rows of small, serrated teeth are replaced throughout life. See do iguanas bite?
• Dewlap: the flap of skin under the chin is used in displays and helps with temperature regulation.
• Long tail: the tail makes up more than half of a green iguana's length and is used for balance, swimming and defense.
• Femoral pores: pores on the inner thighs, larger in males, produce scent-marking secretions. See male vs. female iguanas.

Iguana Behavior Facts

• Sun lovers: iguanas bask to warm up because they cannot make their own body heat.
• Strong swimmers: green iguanas often escape predators by dropping into water. See where iguanas live.
• Fall survivors: green iguanas are often reported to survive falls from heights of 40 feet or more.
• Head bobbing: iguanas communicate with head bobs, dewlap displays and posture. See iguana body language.
• Tail dropping: iguanas can drop part of the tail to escape; it can regrow, but differently. See do iguana tails grow back?
• Cold sensitivity: in cold snaps, wild iguanas in Florida can be stunned and fall from trees. See falling iguanas.

Diet and Life Cycle Facts

• Most iguanas are herbivores, and green iguanas rely on gut microbes to digest tough plant material. See what iguanas eat.
• Female green iguanas dig nests and may lay dozens of eggs, but they do not care for the young. See iguana eggs.
• Hatchlings are bright green and grow fastest in their first few years. See how big iguanas get.
• Males often turn orange during the breeding season. See iguana colors.
• Rock iguanas are among the longest-lived lizards, with a blue iguana reaching about 69 years. See iguana lifespan.

Surprising Iguana Facts

• The marine iguana is the only lizard that feeds in the sea and sneezes out excess salt.
• Marine iguanas can shrink in body length during food shortages.
• The black spiny-tailed iguana is often cited as the fastest-running lizard, at around 21 mph.
• Iguanas live in Fiji, thousands of miles from the Americas. See Fiji banded iguana.
• A pink iguana species lives only on one volcano in the Galápagos. See Galápagos land iguanas.
• In parts of Latin America, iguana is eaten and nicknamed "chicken of the tree." See can you eat iguana?

Quick Iguana Facts for Kids

• Iguanas are lizards, and lizards are reptiles.
• Green iguanas can grow longer than most kids are tall, up to about 6 feet including the tail.
• Most iguanas eat only plants, like leaves, flowers and fruit.
• Iguanas have a tiny "third eye" on top of their heads that senses light.
• Iguanas lay eggs in underground nests.
• Iguanas are great swimmers and use their tails like paddles.
• Some iguanas can drop their tails to escape, and the tail can grow back.
• Marine iguanas swim in the ocean and sneeze out salt.
• Iguanas warm up by lying in the sun.
• Always wash your hands after touching an iguana or anything in its home.

Iguana Records

Record	Iguana
Longest-lived	Grand Cayman blue iguana, about 69 years (captive)
Fastest runner	Black spiny-tailed iguana, often cited at about 21 mph
Only sea-feeding lizard	Marine iguana
Rarest	Contenders include the pink iguana, with estimates of only several hundred left
Most widespread	Green iguana
Farthest from the Americas	Fiji iguanas

Iguanas and People

Iguanas have been eaten, kept and admired for centuries. Today, green iguanas are popular but demanding pets and an invasive species in places like Florida and Puerto Rico, while many island iguanas are among the most endangered reptiles on Earth. Our guides on iguanas as pets, iguanas in Florida and rock iguana conservation cover each side of the story.

How Iguanas Stay Warm

Because iguanas are ectotherms, they control their body temperature through behavior. In the morning they bask in the sun, often turning their bodies to catch the most light, and darken their skin to absorb heat. Once warm, they become active, eat and digest. When too hot, they move into shade, pant with an open mouth or lighten their color. This is why pet iguanas need a basking lamp and a cooler area, as explained in our temperature guide.

Iguana Senses

Sense	What iguanas can do
Sight	Sharp color vision, including ultraviolet; good at spotting movement
Parietal eye	Detects changes in light and shadows from above, such as a passing bird of prey
Hearing	Can hear, with external eardrums behind the eyes
Smell and taste	Flick the tongue to sample scents, using an organ in the roof of the mouth
Touch	Sensitive to touch, especially around the head

What Eats Iguanas?

Iguanas have many predators, especially when young. Eggs and hatchlings are eaten by birds, snakes, raccoons, opossums and other mammals, while adults may be taken by birds of prey, large snakes such as boas, wild cats, crocodilians and people, who hunt iguanas for food in parts of their range. In Florida, raccoons, wading birds, birds of prey, cats and dogs prey on young iguanas, but few predators regularly eat adults.

How Fast Can Iguanas Run?

Iguanas can move surprisingly fast over short distances when escaping danger, sprinting to cover or diving into water. Green iguanas are quick but are not the fastest; that title often goes to their relative, the black spiny-tailed iguana, cited at about 21 mph. Iguanas tire quickly and rely more on climbing, swimming and hiding than on long chases.

Are Iguanas Smart?

Iguanas learn routines, such as feeding times, and many become calmer with familiar people, though iguana-specific research is limited. See are iguanas smart? for what lizard cognition studies actually show.

Frequently Asked Questions

Sources: Florida Fish and Wildlife Conservation Commission, Green Iguana; SeaWorld, Green Iguana; Vetstreet, Top 10 Fun Facts About Iguanas.