Flying Superhero Poo

When superheroes fly, what muscle do they use to fly? Is it one muscle or a combination of muscles? Or is it an organ the rest of us don’t have, like some sort of anti-gravity organ? Or maybe it’s an untapped part of the brain?

What happens if they have to cough, sneeze or poo while flying? What if you’re flying up with the airplanes and you really have to poo? What happens when Tony Stark has to poo?

Maybe that’s why Iron Man has a scowl on his face all the time. It’s actually “poo-face”.