In "Ant-Man," an expert thief dons a special suit that shrinks him to ant size while maintaining his human-size strength. Then he sets off to stop other people from putting the suit's incredibly powerful technology to evil uses.
The actual science propelling the story is, shall we say, rather minuscule. There is a whole script's worth of plot loopholes drawing the noose on the reality of an actual tiny superhero.
Atomic principles make Ant-Man impossible. In order to make a person so small, you'd have to either remove bunches of their atoms or push those atoms closer to together. Start taking atoms out of the human body, though, and there's no telling what you'll end up with — perhaps just a pile of squishy goo. And there's no way to force atoms into closer proximity to each other. Doing so would violate the laws of physics.
There's also the fact that a large biological systems don't necessarily translate into smaller ones. That is, shrinking our brains and limbs to a smaller proportional size doesn't guarantee that those pieces and parts will all work properly. Everything from respiration to blood circulation changes on a smaller scale, and the human body certainly isn't designed to work in the space of a small insect's form.
That means teensy superheroes are impossible. Perhaps you need to set your sights on a larger bug ... like a spider. Like the guy on the next page.