butterflies in stomach? is it possible?

Where'd That Come From?
> Butterflies in the Stomach
How did butterflies get in your stomach? Well, those really aren't butterflies in there. "Butterflies in the
stomach
" is a way of describing those nervous, fluttery feelings you might get before a test or an important game. An imaginative writer created the phrase to
describe the feeling, and people have been using it ever since.
These tummy flutters are normal and happen to many people - even grown-ups. Some people believe having a few butterflies might even help you perform better
by keeping you on your toes.