Doug's in dental school. Dental school requires carving tiny teeth out of wax. Carving tiny teeth out of wax can get a bit dull. So when such times come around, Doug apparently does this:
My favorite? Du-nu-nu-nu-nu-nu-nu... BAT TOOTH!
(If our camera weren't so detail-handicapped, you'd be able to see the carefully carved face. Hilare.)
I was under the impression he was studying when he went to school. Weird.