It's not very useful to tell a child to avoid a bully if you can't tell the child how to do so. Children need to understand there is a very specific course of action to be taken in dealing with bullies and dangerous situations.
Does your child know exactly what to do if he or she is being harassed by a bully? Do they know what to do if approached by a stranger?
These reports and articles can help you inform your child of what to do in such situations.