Our modern medical standards wouldn't be possible without the horseshoe crab. Find out why!

If you really want to strike it rich, don't worry about digging for gold or trying to strike oil. Head to the sea and find yourself some horseshoe crabs to drain and make a killing. It turns out their blood is key in the world's medical arsenal.

The horseshoe crab has a very simple immune system that was discovered in 1971. Its blood binds and clots when it comes in contact with fungi, viruses, and bacterial endotoxins. It contains a compound, Limulus Amebocyte Lysate, or LAL for short, that is an easy way for the Food and Drug Administration to test for any bad stuff in new drugs. Now, every drug and surgical implant certified by the FDA is tested using LAL.

On the world market, a single quart of the crab's blood runs around $15,000, making it an incredible business for those that live where they are abundant. According to the Atlantic States Marine Fisheries Commission, approximately 250,000 horseshoe crabs are needed to fuel the medical testing each year.

There is good news: The blood can be extracted from the little crabby guy without killing them, and there have been no signs of any long-term injury. It's a win-win...sort of.


During the 2011 riots in London, bookstores were the only thing left completely alone!

When chaos strikes and you don’t know where to go, when everyone is rioting and looting, will you join the masses? Where would you loot first to get what you need? The electronics store? Perhaps, a bookstore. No? Neither would any of the 2011 London rioters.

While nearly every other kind of shop from furniture stores to antique shops, was attacked, those who sold the ancient treasure of book-bound knowledge were left completely untouched. While it is an objective fact that books wouldn’t keep you alive or help feed your family during such chaos, this does make an unfortunate statement about the priority of modern global culture.

Some bookstores in London even felt comfortable enough to leave their stores open. One employee figured that it would be a good thing. He even remarked that if they were to steal something from their store they “might learn something.”

Unfortunately, one bookstore was in fact vandalized. It was theorized that the store was attacked because the owners were openly gay.


The inside of an igloo isn't cold—they can get up to 60 degrees! Find out how!

Usually when people picture an igloo, they imagine a dome with a little tunnel attached. This is surprisingly accurate! Igloos are surprisingly hospitable, and it all comes down to science.

Snow makes a surprisingly good insulator. When combined with ice to make the walls of the dome sturdy, it creates a cozy little environment. With the occupant’s body heat and perhaps the use of oil lamps or candles, the walls of the igloo melt a little, but then are soon frozen by the temperatures outside. Several days of this melting and refreezing process creates a nice insulation, sometimes of up to 60 degrees Fahrenheit, which is incredibly welcome when the weather outside is -50 degrees Fahrenheit!


The human eye can spot a candle flame from 30 miles away! Learn more about this amazing organ

Think about this next time you complain that you have bad eyesight! The human eye is incredibly sensitive. It’s theoretically possible to see a candle flame from 30 miles away, and the farthest visible light we can see with the naked eye is the Andromeda galaxy, which is 2.6 million light years away!

Of course, there are some limitations. In order to see a candle flame from so far away, it would have to be completely dark and the Earth would have to be flat--or you’d have to look at it from on top of a mountain during a pitch black night!


Dragonflies are the most effective predator in the animal world. How do other predators stack up?

The world can be a rough place for some animals. The capture of prey is necessary for survival, obviously, but not all species are in the same league in terms of effectiveness.

The dragonfly stands above the rest in this category. They have earned the distinction of successfully snatching about 95% of their targeted food. As if that weren’t a difficult enough task, the fact that their prey is usually captured in midair adds another reason to be in awe of the dragonfly’s unmatched effectiveness.

For some fresh perspective, compare the lion, for instance. It struggles to catch a quarter of all the prey it pursues. To take another example, look at the great white shark. For all its fearsomeness, it still manages to catch only about half the prey it goes after.

So what is the key to the dragonfly’s success? Scientists have found that they possess a nervous system that allows them to focus sharply on a single object. The neurons that connect the dragonfly’s brain to its flight motor center create a unique ability to follow a moving target, calculate its future position, skillfully change flight paths, and finally, capture a meal.

Then the process starts over again. Dragonflies go beyond having the capacity to capture prey just once. They have an appetite that can seem nearly impossible to satisfy.