When children of any age temporarily disappear for any reason -- as in the case of the three year old who dashes off down the street, or the teenager who stays out overnight without phoning -- parents' feelings of panic and fear are unimaginable -- unless you've been through it yourself. Clearly, if a child disappears (at any age) for a long period of time, you must contact the police. But often children run off temporarily, and parents must consider how to handle these incidents based upon the age of their child.