Belonging to a group of insects known for long-distance travel, the monarch butterfly is famous across Canada for a migration unmatched by any other insect on the continent. Monarchs are found in much of North America, but the eastern group breeds across southern Ontario and Quebec each summer before it heads south. Scientists once knew very little about where these butterflies went, and it was only in the past few decades that researchers traced the full route. Monarchs are easy to know by their bright orange wings, which are crossed by black veins and edged with white spots, a pattern that warns predators of the toxins stored in their bodies.

The monarch passes through four stages in a single life cycle: egg, larva, pupa, and adult. A female lays her tiny eggs only on milkweed, the single plant her young can eat. Each egg hatches into a striped caterpillar, or larva, which feeds steadily and sheds its skin several times as it grows. The caterpillar then forms a green chrysalis, inside which the insect goes through a complete change known as metamorphosis. About two weeks later, a grown adult comes out, and its crumpled wings expand and harden before its first flight.