Question: ink glands in cephalopods are used mainly for
[{'answer': 'to confuse predators', 'provenance': [{'wikipedia_id': '2957131', 'title': 'Ink sac', 'start_paragraph_id': 1, 'start_character': 340, 'end_paragraph_id': 1, 'end_character': 360, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2957131', 'title': 'Ink sac', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 360, 'bleu_score': 0.9274581800092581, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7870724532253261249}, 'section': 'Section::::Abstract.'}]}]