Already at an early stage, caterpillars of Monarch butterfly feed on milkweed plants. They take in the plants' toxins, against which they themselves are immune. This image is from Nature's Greatest Talents: The Art of Seduction.
During nights, termite mounds may be the perfect place to watch a glowing spectacle: when young glow worms use it as a stage and show off their yellow-green lights. This image is from Nature's Greatest Talents: The Art of Seduction.