Dr. Henry Pym isolates particles into a serum which allows him to shrink to the size of the ant (a second embryo restores him to regular size). Pym afterwards develops a helmet which enables him to communicate with and control ants and to amplify his voice so that he can be heard by people when he is shrunken. Having a supply of decreasing fluids (later capsules) in his belt, he also tackles crime as Ant-Man, facing a number of Marvel's more colourful villains, such as Egghead, the Porcupine, the Human Top, along with the Living Eraser.
He is afterwards accompanied by Janet van Dyne, the spoiled daughter of a scientist, who associates with Pym to avenge the death of her father. Pym subjects her to a process which grants her the ability to shrink and grow wings. Calling herself the Wasp, she and Ant-Man conquer the alien that killed her father and banish it to another dimension; this adventure lays the groundwork that the two then share. Man and the Wasp became founding members of the Avengers, and much of their success over the decades would be tied to this group.