Idaho Code § 20-515

If any person summoned as herein provided shall, without reasonable cause, fail to appear, he may be proceeded against for contempt of court. In case the summons cannot be served, or the parties served fail to obey the same, or in any case when it shall be made to appear to the judge that the service will be ineffectual, or that the welfare of the juvenile offender requires that he be brought forthwith into the custody of the court, a warrant or a capias may be issued for the parent, guardian or the juvenile offender.