Rudd, 47, reprises his role as thief-turned-Ant-Man hero Scott Lang in the third installment of the Captain America trilogy, and told The Graham Norton Show that he felt like a 10-year-old boy while on set, reported Contactmusic.
"We shot Ant-Man - but I was alone in a bubble. And all of a sudden I'm standing around seeing Robert Downey Jr in the Iron Man suit, and seeing Chris Evans," Rudd said.
"And they're all there. I've seen the movies. I felt like I was 10 years old. It was crazy. It was pretty cool.