Early American humans hunted car-size armadillos and used their shells for houses.
12
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Crying literally alleviates stress and uniquely allows humans to decrease feelings of anger and sadness.
24
Tigers can see 6 times better at night than humans.
305
Pain occurs when sounds are above 130 db.
124
Humans are capable of running 40 mph according to a study by bio-mechanical expert Dr. Matthew Bundle. Today's fastest man, Usain Bolt, has a top speed of 28 mph.
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