Your thumb is about the same size as your nose.
124
Yawns are more contagious among people with closer relationships.
163
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
If your DNA was stretched out it would reach to the moon 6,000 times.
256
The average sperm cell swims at 8 inches per hour.
76
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Your heart will pump about 212 million liters in its lifetime.
26