Wanna play in my sandbox?

Is it safe for kids to eat sand? Zachary really seems to be enjoying eating sand. He does so in such a supremely cute way that I just let him, because I just can't stop the cuteness. I fill up his pail with sand and then he bends over to inspect the sand and leans into the pail, sticks out his tongue and tries a mouthful of the sand. Much too funny. His other sand eating technique is to take his wet hand and plant it firmly into the sand, thus coating his little hand with a fine layer of sand. He then take his hand to his mouth and licks it all off. That elicits a look to me that is then followed by the sweetest giggle and then mommy-heart-melting! I really hope the sand tastes like sugar.