Humans are constantly shedding particles of skin throughout the day. You'll mainly notice this when you get out of the bath or shower. By the time you're 70 years old, you will have shed around 100 pounds of skin.
"Ahu" are stone platforms on which many moai sit. There are 313 known ahu and 125 of these carry moai. The biggest, Ahu Tongariki is 220 m (720 ft), and had the most (15) and tallest moai.