I was reading on here recently about how the concept of Stranger Danger is not useful - children might need the help of a stranger, emergency services are strangers, bad people aren't always strangers etc - but that a better approach is Tricky People. Tricky people don't ask children for help (come look for my puppy) etc. I've started trying to talk to my almost four year old but I'm not sure it's going in AND I don't want to scare him to death. Does anyone know of good books for that age?