Order reversed, and fact-finding determination vacated, without costs or disbursements, and matter remitted to the Family Court, Westchester County, for appointment of a guardian ad litem and a new fact-finding hearing, in accordance herewith. It was error for the court to accept appellant's admission of the allegations against him without first requiring a "reasonable and substantial effort" to notify his parents, and then appointing a guardian ad litem, if such effort proved unavailing (Family Ct Act, § 741, subds [a], [c]). The obviously antagonistic position taken by the school in whose custody appellant was then placed renders the presence of its officials an inadequate substitute. Accordingly, appellant is entitled to a new hearing at which he will have the guidance of the appointed guardian (see Matter of Myacutta A., 75 A.D.2d 774). Titone, J.P., Lazer, Mangano and Thompson, JJ., concur.