About a week ago, I heard Drew exclaim, "Did someone cut your hair?!" Though I looked at her head, evidently I was looking in the wrong place, because I didn't see any difference in Z's hair. After a few days, however, it started to occur to me, "Did she always have those bald spots on the left side of her head?", immediately above her ear and a smaller one behind. Both G and BB adamantly denied having done the shearing; I quickly banned everyone from scissor usage until someone was willing to fess up. (There was also another incident during that same time in which BB was caught cutting something other than paper, not Z's hair.)
A few hours after I took the top photo, Z presented me with this handful of her hair, which she said she "found behind the couch". Case closed.