Codes, puzzles and cryptic public art tease us with their intrigue. Here's our list of 10 of the world's most cryptic unsolved mysteries and codes.

Cactus leather can be used for handbags, shoes, furniture, and more. We look at its environmental impact and how it compares to cotton and leather.

A Brief History of Zoos Humans have kept wild animals for thousands of years. The first efforts to keep wild animals for non-utilitarian uses began about 2,500 BCE, when rulers in Mesopotamia ...

Freder / Getty Images A conservationist by the name of Hector Ceballos-Lascurain is often credited with the first definition of ecotourism in 1987, that is, “tourism that consists in travelling ...

Artush / Getty Images The largest alligator ever measured was 15 feet, nine inches long, and weighed in at 1,011.5 pounds. This gator was caught in Mill Creek, a tributary of a river in Alabama ...

Roberta Murray / Uncommon Depth / Getty Images The taiga is not an easy place for amphibians to live, thanks to its cold winters and short summers, but a few still eke out a living here. One is ...

Textiles are recyclable. Here's some important info on how to recycle your old clothes, sheets, towels, and more—plus, smart and eco-friendly ways to repurpose them.

The killing of wild animals for food is a different story. Though it was, at one time, a way of life and necessary for survival, today, hunting is a controversial topic because it is frequently ...

Animal testing remains legal in most of the world. Learn how the practice began—and is still performed—and how to know if your favorite cosmetics have been tested on animals.

Palm oil is cheap and comes from a highly efficient oil palm crop that produces generous yields, year-round, with relatively little land. Yet, it can be horribly unsustainable. Demand for the ...

Treehugger / Sanja Kostic To get the most out of exfoliation, you need to know your skin type. Your skin is unique and will respond well to some exfoliants and poorly to others. Skin types are ...

Red pandas are endangered with their numbers decreasing. The World Wildlife Fund estimates there are fewer than 10,000 left in the wild.