Butterflies do not have actual mouths, however they do have a kind of tongue called a hibiscus (spelling?) however this is not how they taste. Butterflies use their feel to taste the nectar in flowers before they eat it. They also use their antennas to kind of smell things.
They taste with there mouth duh?
That was a very rude way to answer this person's question. They don't exactly have a mouth, they have a straw curled up under their head that extends to suck up whatever they wish to eat.
No you complete and utter idiot they taste things with their feet. And that is true - don't always go to the obvious conclusion.