happy faces in the sand

Thomas' favorite things to draw these days are faces. Every card and/or letter gets a smiley face on it, he draws them on paper and cuts them out to give them away, he constructs them out of different materials, and this afternoon he drew them in the sand all over the beach. This one was especially interesting and when I pointed out that he gave the face eyebrows he said, "Yes! Eyebrows, a nose brow and I'm going to give him a mouth brow, too!" Okay, a mouth brow I can understand, but what the heck is a nose brow?? He says he has seen them, but I don't know where that would have been...