Fingernails grow nearly 4 times faster than toenails.
31
Some people have a "natural alarm clock" allowing them to wake up when they want. This is actually caused by a burst of the stress hormone adrenocorticotropin.
15
Brain scans show that people who view photos of a beloved experience an activation of the caudate - the part of the brain involving cravings.
103
Dating back to the 1600's, thermometers were filled with Brandy instead of mercury.
16
All humans have the ability to see ultraviolet light, but it is passively filtered out by the eye's lens. People who undergo surgery to remove the lens can detect ultraviolet light.
21
There is a disease called ichthyosis that turns the skin scaly like a fish.
90
A toothbrush within 6 feet of a toilet can get airborne bacteria from flushing.
15
