Dolphins use sound to 'see' inside objects — their echolocation can detect the bones inside a fish.

Sea turtles can migrate thousands of miles between feeding and nesting areas.

Bioluminescence allows some deep-sea creatures to produce light.

Octopuses have demonstrated short-term and long-term memory.

Certain birds migrate seasonally to access food sources.

Nostalgia was once classified as a medical disorder — Swiss physicians in the 17th century believed it was a brain disease.

Octopuses can squeeze through tight spaces due to their soft bodies.

A group of jellyfish is called a smack.

There are underwater waterfalls caused by differences in water density.