If your 16 year old won't come home, the first thing you should do is try to talk to them. If they're not willing to talk, then you can consider contacting their friends or other family members to see if they can help convince your child to come home. If all else fails, then you can always contact the police. However, keep in mind that filing a missing persons report should be considered a last resort since it may make your child more reluctant to come home.