"We come onstage, and we create a cartoon world that can't exist without sound," Dundas explains. "There's one microphone, and I create sound effects while Dave acts out the stories.
"We're the loudest mimes in the world, I guess you could say, because we add sound effects."
Naturally, it's only a matter of moments before sibling rivalry rears its hideous head.
"Whoever has the microphone essentially creates the universe," Dundas says. "Throughout the show, Dave is trying to get the microphone back from me . . . I can make a rabid monkey appear in front of him. I can make him get run over by a truck. I create a sound effect, and he's got to react to it. By the end of the show, we're vocally and physically battling with each other. One review said it's like watching Daffy Duck and Elmer Fudd on the set of Terminator 3. That was nice."
Dundas adds that another reviewer likened the performance to "Marcel Marceau on really good drugs."
Which reminds him of an anecdote. Several years ago at the London International Mime Festival (the silence must be deafening!), Dundas came upon Marceau -- the world's most (and only?) famous mime -- rehearsing his act.
"At a certain point, a piece of scenery didn't appear when it was supposed to, and Marceau just suddenly started swearing really loud in French . . . it shocked me."
It's this element of the unexpected, according to Dundas, that drives every Umbilical Brothers performance.
"We lull you into thinking you're watching a certain kind of show, then we take it off on a tangent."
Indeed, the boys have been taking tangents since meeting in a Sydney acting class in 1988. "We were intending to be serious actors, and something went desperately wrong with that plan," Dundas remembers. "We started goofing off in class, making fun of the mime classes, and people laughed at what we did."
And what's with the womb reference? "We were looking for a name that crystalized the link between us," Dundas explains. "If one of us does something onstage, the other one has to react . . . the umbilical cord is there, between us."
So the boys are bound by a strong brotherly bond, but is their irreverence alienating them from mime culture?
"Mimes really like our show," Dundas insists. "They'll come away with a few new ideas, actually, and goddamnit, they need new ideas. I mean, how many decades have they been walking against the wind, for God's sake?"