Spider monkeys live in groups and eat mostly fruit, nuts, seeds, insects, and eggs. Capybaras can weigh up to 100 lbs, stand 2 feet tall, and eat grasses and plants. Electric eels can grow to 8 feet long and weigh 60 lbs, and produce shocks when surprised. Piranhas have razor sharp teeth and eat meat from aquatic and land animals in the water. Caimans are most active at night when they hunt with their 75 sharp teeth.