Another child and distraught mother materialized right at closing time this week. “He cannot go back to school until it is treated!" the tired working mother bemoaned. Head lice are the scourge of grade schools everywhere, from the ritziest private schools on down. And they are not going anywhere anytime soon. While harmless to the kid, adults go berserk—casting glances of judgment upon the family and banning the child from school and social events. Parents take it particularly hard and are start harboring deep feelings of guilt and question how hygienic their homes and housekeeping skills really are.