Episode five covers the Amazon rainforest, home to more varieties of plants and animals than anywhere else on Earth. Despite the profusion of life, finding food can be a challenge for both people and animals. Many plants have poisonous leaves, seeds and fruit to protect themselves against attack. The Guarani, a native tribe, practise low-impact hunting using blowpipes. They make darts using downy fibres from kapok seeds for the flights, and dip the tips in natural toxins. Some animals eat only the youngest shoots, which contain less poison. Others such as white-faced sakis have developed special digestive systems to cope with their toxic diet. At a clay lick, spider monkeys risk descending to the forest floor to eat clay, which helps to neutralise the toxins. They are not alone - other visitors include a brocket deer, white-lipped peccaries and parrots. At night, the flooded lick is visited by the shy Brazilian tapir. Red-and-green macaws take clay at special places along the rivers, a great social occasion for the birds. Army ants are shown overwhelming their prey, but some creatures have developed clever ways to avoid detection. Antbirds are reliant on the ants to flush out fleeing insects. In the canopy, bromeliads are a vital water source for all tree dwellers, including woolly monkeys and the dazzling paradise tanager. Each plant can store up to ten litres and is a microcosm of life. Golden-mantled tamarins are successful because they are supreme opportunists, eating fruits and insects and living in tightly-knit groups.