is this NORMAL??

So Trey has definatly made it a daily activity of his to eat dirt. Yes you read correctly, I said EAT DIRT!! There isn't a day that goes by that I don't find Trey with a mouth full of dirt. I am wondering if this is normal with boys or if Trey has developed a great taste for dirt? Man, I am still getting use to the BOY thing. Raising a boy is totally different then raising a girl in sooooo many ways.