Ds is 4.5, very confident, curious, sociable and loves meeting and speaking to new people. He is also very innocent and we've never given him reason to distrust people or told him bad people exist. Obviously we've told him what to do if he gets lost, but not how to react if he's approached by a stranger. Tbh I know that warning him would result in lots of questions I wouldn't have a clue how to respond to, such as why are some people bad and in what way are they bad etc. I don't want to scare him or curb his confidence around others but i need an age appropriate way of teaching him these really important safety messages. Are there any children's books anyone can recommend? How have you tackled it?