The story
The northward migration of eastern monarchs unfolds across generations. Butterflies lay eggs on milkweed, and their offspring continue the journey.
A later generation returns south to overwinter in Mexico. The full cycle connects places far apart through the lives of small insects.
The relay depends on food along the route. Caterpillars eat milkweed, while adults drink flower nectar. A place with flowers but no milkweed cannot meet every need: the next generation needs its own food, too.
