Yawns are more contagious among people with closer relationships.
163
It takes approximately 12 hours for food to entirely digest.
93
Only humans shed emotional tears.
331
Pain occurs when sounds are above 130 db.
123
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Tigers can see 6 times better at night than humans.
305
Enamel is hardest substance in the human body.
61