Blue blood may look alien, but it’s one of evolution’s most elegant solutions to life in extreme environments. Here’s how evolution rewrote the rules of oxygen transport.

Some animals do not have red blood like humans. From spiders to octopuses, their copper-rich blue blood helps them survive ...

Lions are often called the “king of the jungle” for good reason. These impressive predators are incredibly powerful. A male lion can stand up to 4 feet tall at the shoulder, have a 10-foot-long body, ...

Some animals survive by living inside other creatures. From parasites to unlikely partners, these seven species turn living ...