Interesting....

Monarch butterflies use milkweed as a self-defense for survival. Monarch caterpillars love to eat milkweed leaves. These leaves contain toxins and poisonous chemicals. The toxins do not harm the caterpillar, however they do make the caterpillar poisonous to most predators. Because it eats milkweed leaves as a caterpillar, the monarch butterfly is also poisonous.