The average sperm cell swims at 8 inches per hour.
76
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
The human brain doesn't stop developing until about 25 years old.
102
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73