20 November 2014, 09:50 PM ET
Orcas, or killer whales, are the largest of the dolphin family.
20 November 2014, 09:40 PM ET
The endocrine system is a collection of glands that secrete hormones.
20 November 2014, 09:12 PM ET
A urinary tract infection is an infection of any part of the urinary tract, which includes the bladder, kidneys, ureters and urethra.
19 November 2014, 08:26 PM ET
The Brazilian wandering spider is one of the most venomous spiders on Earth.
19 November 2014, 08:49 AM ET
Copperhead snakes are common in North America, and have the distinction of biting more people in the United States than any other snake.
18 November 2014, 11:26 AM ET
Koalas are an Australian icon that have a keen sense of smell, eat mainly eucalyptus leaves and have fingerprints like humans!
15 November 2014, 02:01 AM ET
Mermaids — legendary half-human, half marine creatures — have fascinated people for centuries and inspired many "sightings."
14 November 2014, 06:32 PM ET
These solitary spiders like to hide in dark places in the house. Their bite is very venomous.
13 November 2014, 11:00 PM ET
Moose are the largest members of the deer family. Their antlers get shed every winter, and new ones grow back in spring.
13 November 2014, 10:56 PM ET
Most bug bites and stings are usually just uncomfortable. However, some people are allergic to the venom of certain insects or spiders and can have severe, even life-threatening reactions.
12 November 2014, 08:29 PM ET
These ocean-dwelling mammals evolved from ancestors that lived on land!
11 November 2014, 10:17 PM ET
Huntsman spiders are long-legged predators that hunt down their prey. One species of huntsman spider has a leg span of 12 inches — or as big as a dinner plate.
11 November 2014, 10:10 PM ET
Droughts are one of the most damaging types of weather-related phenomena, but classifying them is difficult.
04 November 2014, 10:56 PM ET
History, properties and uses of the element boron.
04 November 2014, 08:46 PM ET
There are 40,000 types of spiders in the world. All of them bite, but spider bites are rarely deadly.
04 November 2014, 07:33 PM ET
400,000 Americans have MS
03 November 2014, 08:26 PM ET
Ovarian cancer occurs when cells in one or both ovaries proliferate out of control.
01 November 2014, 02:47 AM ET
The strong nuclear force is one of the four fundamental forces in nature. It is responsible for binding together the fundamental particles of matter to form larger particles.
31 October 2014, 11:42 PM ET
Great white sharks are the largest predatory fish. Often thought to be man-eaters, they are actually responsible for only five to 10 attacks on humans per year.
31 October 2014, 10:49 PM ET
The legend of a sunken civilization has captivated imaginations for centuries.
31 October 2014, 10:30 PM ET
There are several things a man can do to increase the chances that he will get a woman pregnant.
31 October 2014, 10:22 PM ET
The large carnivorous dinosaur reigned during the late Cretaceous Period, 65 million years ago.
31 October 2014, 10:13 PM ET
Stroke, the No. 4 cause of death in the United States, occurs when the flow of blood to the brain is disrupted.
30 October 2014, 11:51 PM ET
Spinosaurus was even bigger than Giganotosaurus and Tyrannosaurus.
30 October 2014, 11:48 PM ET
They may look slow and lumbering, but these amphibious beasts can be intimidating!
30 October 2014, 10:16 PM ET
Colon cancer, the second leading cause of cancer deaths in both men and women, can be flat or look like a cauliflower stalk.
29 October 2014, 09:38 PM ET
For a woman trying to get pregnant, there are a number of ways to increase the chances and make it more likely that she will conceive a child.
29 October 2014, 09:12 PM ET
Black widows are spiders that are known for the females' unique appearance and tendency to eat their mates.
29 October 2014, 06:51 PM ET
Amelia Earhart's disappearance during an attempt to fly around the world remains a mystery, but recent expeditions may have found clues to her fate.
28 October 2014, 10:18 PM ET
They're the tallest animal on Earth with necks that are 6 feet tall!
28 October 2014, 09:58 PM ET
Properties, sources and uses of the element chlorine.
24 October 2014, 04:10 PM ET
The fictional Dracula was loosely based on a real person with an equally disturbing taste for blood: Vlad III, Prince of Wallachia or — as he is better known — Vlad the Impaler (Vlad Tepes).