Actually, butterflies do not eat at all. Well, at least not in the traditional sense. What do butterflies eat? Instead of eating, butterflies get their nurishment from drinking. They have a long narrow tube in their mouth called a proboscis that acts as a straw. They usually set on top of a flower and drink the nectar. To see a congregation of many kinds of butterflies together they feed on small puddles on the grouind or wet areas on leaves and plants.