Enamel is hardest substance in the human body.
61
The average sperm cell swims at 8 inches per hour.
76
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
One human hair can support 3 ounces.
191
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
Poor eyesight (myopia) is associated with higher IQ.
232