The last time I was hanging around little kids one of them ran up to someone and warned him that other kids nearby where misbehaving. I can't remember the exact details of the misbehavior; it was something unpleasant but not life-threatening. Maybe they were tearing up the garden, but they weren't doing it with a giant earthmover or anything. Anyway, the guy said to his kid, "Don't be a tattletale," and the kid ran off. I remember hearing that back when I was a little kid. I never understood it then, and I still don't understand it now. I think you'd want to turn your kid into an informant, someone to key you into the crazy stuff that only he or she knows about. It's not like we're all in mafia families or something where we have to keep huge secrets.