The other night, after trying desperately for an hour to make my daughter go to sleep by scaring her of ghosts, I told her that if she doesn't go to sleep, "drones of USA" might come. On hearing this, she immediately closed her eyes and was sound asleep within minutes. A practical and effective advice for mothers dealing with problematic children. -DR IRFAN ZAFAR, Islamabad, via e-mail, February 23.