These unforgettable viral videos show animals at their cutest and at their most human. These are the adorable memes that just keep going and going.

Unseasonably cold weather and globally warm scenarios pose grave animal dangers to tropical fish, sea turtles, colobine monkeys, gorillas and other marine animals.

These spiders' bold faux faces and smile-like markings aren't there to make you laugh, instead they serve to scare and confuse potential predators.

Our bodies contain more bacteria cells than human cells. They're in our mouths and guts, on our skin, and they can both help us and hurt us.

Seemingly mild creatures like cleaner fish, damselfish and fruit flies have recently shown that they have surprising wild sides when push comes to shove.

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.