Arachnophobia: the irrational fear of spiders. These hairy 8-legged, multi-eyeballed spiders may inspire fear, but get up close and they look almost cuddly.

From past (venomous dinosaurs) to present (venomous jellyfish) to future (venom treatments), the evolution, dangers and benefits of venom continue to surprise.

Mundane subjects like feathers, human taste buds and a drop of pond water become utterly fascinating and even beautiful when photographed with microscopes.

From insects and brain size to genetically-altered mice and Alzheimer's to sea lions and toxic brain damage, these animals help educate about the brain.

Using 25 of a cat whisperer's extraordinary images, here are 10 large cats we might not normally get close enough to say, here kitty kitty, smile for the camera.

Size DOES matter: These 9 amazing animals prove that when the going gets tough, the tough get big!

Living organisms continue to amaze in the form of recent bizarre discoveries surrounding lungless worms, lonely bacteria and coconut-crazy octopuses.

Relatively unchanged for millions of years, these very "living fossils" have each managed to find a successful ecological niche and have stuck with it.

From a man-sized flower that smells like rotting corpses to a pitcher plant that eats rats, these 15 plant species are among the most unusual in the world.

For people uninterested in fighting for the hottest toy or gadget, considering dogs, cats or other animals as holiday gifts may be a cool approach this Christmas.

Polar bears are the top predator in the arctic marine ecosystem. But thanks to mankind, these magnificent animals are headed for extinction.

These 10 invasive species are infamous for the environmental destruction they have caused, even when introduced with the best of intentions.

Deforestation, global warming and other climate changes could have serious effects on dolphins, amphibians, turtles, penguins and many other animals.

Animals are more than just our companions. We share a planet with them, and they often clue us in to fascinating new environmental knowledge.

When we think of slugs, most of us picture the small land variety. But in the ocean waters lives a whole other world of colorful, fascinating sea slugs.