Yawns are more contagious among people with closer relationships.
163
The average sperm cell swims at 8 inches per hour.
76
Enamel is hardest substance in the human body.
61
The human brain doesn't stop developing until about 25 years old.
102
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193