Ara macao individuals gather in flocks to sleep at night, but maintain a monogamous pair bond for life. Mates may show affection by licking each other's faces and mutual preening. Once paired with a mate, they are rarely found alone except to feed when one bird must incubate the eggs. Nests are made in hollowed areas in trees, usually in the upper canopy of rainforests. There, in the protection of the thick foliage, they are camouflaged so predators are less likely to spot them. Typical predators of Ara macao are monkeys, toucans, snakes, and other large mammals. If scarlet macaws are in the nest and frightened by something, they will cautiously inspect the scenario until the danger is gone. If the nest is directly threatened, the macaws will quietly escape to safety one at a time.

Scarlet Macaws, and parrots in general, frequently use their left foot in handling food and in grasping other things. The right foot supports their body when they are utilizing the other leg as an appendage to aid the beak. This left handed condition seems to be based on the same principle as the preferential hand that humans utilize. This may be due to the development of the macaw's right side of the brain over that of the left side.

~ ADW