The act of breast-feeding is so fundamental to being a mammal that we named ourselves after it. (“Mammalis” translates to “of the breasts.”) But over time, scientists have discovered that other ...

When the 18th-century biologist Carl Linnaeus classified a group of animals as “mammals,” he based the name on one key characteristic—mammary glands, from which females produce milk to feed their ...

Encountering a jumping spider might give some people a start, but researchers are interested in these agile arthropods, especially their ability to plan and execute complex behaviors. Scientists are ...