What's the 'tail' of the butterfly's wings called?

Question

What's that part called? The parts at the ends of the wings that extend out, like little tips or tails. I think it's named after a certain bird's tail or something.

I'm talknig about the things that this butterfly sketch has: http://etc.usf.edu/clipart/3200/3236/butterfly_3_lg.gif

and what's the purpose?

Thanks ~

Answer 1

Hi! I think they are called "Swallowtails."  I know there is a Tiger Swallowtail, and a Zebra Swallowtail. The Zebras are my favorite!