While not in flight, adult morphos tend to stay hidden on the ground with their wings closed, exposing only the drab undersides in an effort to foil birds like jacamars and flycatchers, which prey upon them. The bright blue coloration that distinguishes morphos is not due to blue pigment. Rather, it is the result of microscopic ridges on the butterflies' wing scales that scatter and reflect light. The generally duller-coloured females have broader, less graceful wings than do males.

Except for some morphos that rarely descend from the treetops, most adults feed on fallen fruit as well as mud and carrion. The females are most active at midday, searching for the right plants on which to lay their dome-shaped eggs. The larvae eat several species of leguminous plants, and each egg is laid singly on the underside of a leaf upon which the hatchlings will feed. The caterpillars live in a communal web and are mottled red and yellow, with black heads covered with irritating hairs. After attaining a third-instar length of 9 cm (3.5 inches), the caterpillar creates a light green oval chrysalis from which it will emerge as a butterfly. The life cycle from egg to adult is 115 days. Morphos are bred commercially for decorative use in items such as display boxes, jewelry, lampshades, and inlays.