Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
The largest cell in the human body is the female egg and the smallest is the male sperm.
682