Input (grade 10): Although they belong to the class of arachnids, harvestmen are not spiders, which are of the order Araneae rather than the order Opiliones.
Output (grade 6): They belong to the order Opiliones. Although they belong to the class of arachnids, harvestmen are not spiders. Spiders belong to the order Araneae rather than the order Opiliones.