What makes butterflies that eat milkweed dangerous to there preditors?

The monarch caterpillar is at a high risk when they eat Milkweed. Milkweed got its name because its full of a sticky milk colored liquid. Many caterpillars get stuck in it and die. The caterpillars that eat milkweed are immune to a special toxin in the milkweed but still are at risk of dying in the sticky liquid. Butterflies do not eat milkweed. They drink nectar from flowers or juice from fruits.