Monarch caterpillars eat milkweed the way a cat eats tuna, but a kitten can grow on a diet of many protein sources. Monarch caterpillars can grow only on a diet of milkweed

Please click on individual images to enlarge view of the seed pods of the common milkweed, aka Asclepias syriaca, and a nearly mature monarch caterpillar working on the top of a nearby plant from which the flowers and seed parts are already gone. The monarch that develops from this caterpillar will need to find more milkweed vegetation on which to lay its eggs. The next generation will be the ones that migrate south in the fall to overwinter in Mexico and return north in spring. For authoritative information on monarchs and milkweed, please see Monarch Watch.