Piranhas are widely notorious for their fierce behaviour. They are also capable of communally devouring prey much larger than themselves, such as capybaras, cows or people. This is possible because their jaws are lined with extremely sharp, triangular teeth that can cut through flesh. Normally they also eat small animals, however, such as insects, small aquatic animals, fish, seeds and fruit.
Their eggs are sticky and attach to underwater tree roots. The male in particular guards the eggs, which hatch after 9-10 days.
 
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