Due to the small budget and experimental nature of the original Ant-Man film, it did not have any major cameos by other Avengers, save for Captain America’s sidekick Sam Wilson aka The Falcon.
This relationship began in Captain America: The Winter Soldier, and was firmly in place during Captain America: Civil War, which saw Steve, Sam, and Black Widow recruiting Ant-Man to their team when it was time to take a stand against Iron Man’s group.
Now, director of the film Peyton Reed has revealed there was another secret Avenger cameo during the battle between Ant-Man and Falcon.
There is some hope that Sam, Steve, and Nat will be reunited in the upcoming Black Widow solo film, which takes place between the events of Captain America: Civil War and Avengers: Infinity War, even if it is only in the form of flashbacks.