Yawns are more contagious among people with closer relationships.
163
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
The average sperm cell swims at 8 inches per hour.
76
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The average person's skin weighs twice as much as their brain.
131
Your body is creating and killing about 2.4 million red blood cells per second.
17
The human brain doesn't stop developing until about 25 years old.
102