25 Octopus Facts for Kids That Are Weird, Smart & True

Octopuses are some of the strangest and smartest animals in the ocean. They have eight arms, three hearts, blue blood, powerful suckers, flexible bodies, and skin that can change color and texture.

These octopus facts for kids focus on real anatomy, behavior, camouflage, movement, intelligence, and life in the ocean. The facts were checked against trusted sources including the Smithsonian Ocean Portal and Monterey Bay Aquarium.

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Quick Octopus Facts for Kids

1. Octopuses have eight arms. Unlike squid and cuttlefish, which also have two specialized tentacles, octopuses have eight sucker-lined arms.
2. Octopuses are mollusks. They belong to the cephalopod group, making them relatives of squid, cuttlefish, nautiluses, clams and snails.
3. There are roughly 300 known octopus species. The exact number can change as scientists describe new species and revise classifications.
4. Many octopuses have no hard internal shell. Their soft bodies help them move through tight spaces that would stop a rigid-bodied animal.
5. An octopus has a rectangular-looking pupil. Cephalopod eyes can be surprisingly complex even though their visual system evolved separately from ours.

Sources: Smithsonian Ocean Portal.

Amazing Octopus Body Facts

6. Octopuses have three hearts. Two branchial hearts move oxygen-poor blood through the gills, while a systemic heart pumps oxygen-rich blood through the rest of the body.
7. Octopus blood is blue. It uses a copper-containing oxygen-carrying molecule called hemocyanin rather than the iron-based hemoglobin that makes human blood red.
8. Octopus suckers can create a powerful seal. Muscles inside a sucker lower the pressure in its cavity so surrounding water pressure helps hold the sucker against an object.
9. Octopus arms are extremely dexterous. They can be used for walking, gripping prey, exploring objects and handling things.
10. Much of an octopus nervous system is outside the central brain. Smithsonian notes that cephalopods can carry about two-thirds of their neurons in their arms rather than their head.

Sources: Smithsonian Ocean Portal.

Smart and Sneaky Octopus Facts

11. Octopuses can solve problems. Researchers and aquarium caretakers have observed octopuses opening jars, learning tasks and investigating unfamiliar objects.
12. Some octopuses use tools. Smithsonian describes veined octopuses carrying empty shell pieces that can later be used as portable shelter.
13. Octopuses can change skin color very quickly. Pigment-filled cells called chromatophores expand and contract to reveal or hide different colors.
14. They can change skin texture too. Muscles can alter small projections called papillae, helping an octopus resemble rocks, coral or other uneven surfaces.
15. Some octopuses imitate other animals. The mimic octopus can change its posture, color and movement to resemble several different marine animals.
16. Many octopuses release ink when threatened. The dark cloud can create a visual barrier while the animal escapes.

Sources: Smithsonian Ocean Portal and Smithsonian Magazine.

How Octopuses Move and Hunt

17. Octopuses can use jet propulsion. They draw water into the mantle and force it out through a funnel, or siphon, pushing the body in the opposite direction.
18. Bottom-dwelling octopuses often prefer to crawl. Many use their arms to move across the seafloor and save jet propulsion for faster escapes.
19. Octopuses are predators. Depending on species and habitat, they can eat crabs, clams, snails, shrimp, fish and other animals.
20. An octopus has a strong beak. Giant Pacific octopuses can pull prey apart, bite into shells, or scrape and drill through hard shells using their beak, saliva and rough radula.
21. Some octopuses leave “rubbish piles” outside their dens. Scientists can study these shell piles, called middens, to learn what an octopus has been eating.

Sources: Smithsonian Ocean Portal and Monterey Bay Aquarium.

Giant Pacific Octopus Facts

22. The giant Pacific octopus is the largest octopus species. Monterey Bay Aquarium reports that adults can weigh more than 50 pounds.
23. Its arms can span more than 13 feet. Typical reported arm spans range from about 7 feet to 13 feet or more.
24. A female giant Pacific octopus can have thousands of suckers. Monterey Bay Aquarium reports about 2,240 suckers across the eight arms of a female, with males having roughly 100 fewer.
25. A giant Pacific octopus starts life incredibly small. It hatches from an egg about the size of a grain of rice, and a newborn’s eight arms already carry tiny suckers.

Source: Monterey Bay Aquarium.

Where Do Octopuses Live?

Octopuses live in oceans around the world. Many species spend most of their time on or near the seafloor, hiding in dens, rocky crevices, reefs or other shelters. Some deep-sea octopuses live thousands of feet below the surface.

The giant Pacific octopus lives across the North Pacific from Japan and Korea to Canada, the United States and Mexico. Monterey Bay Aquarium reports that it can occur from shallow water to depths of about 4,900 feet.

Why Octopuses Are So Interesting

An octopus combines features that seem almost impossible in one animal: distributed nerves, flexible arms, powerful suckers, rapid camouflage, blue blood, three hearts and strong problem-solving abilities. That makes octopuses useful animals for learning about anatomy, behavior, evolution and ocean ecosystems.

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