Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain doesn't stop developing until about 25 years old.
102
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
One human hair can support 3 ounces.
191
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Your body is creating and killing about 2.4 million red blood cells per second.
17