Sam and Ren, 17-months-old, were caught on camera by their mother, having what's obviously a very intense conversation.
She posted the video on YouTube, where thousands of people have watched it.
As cute and funny as the video is, doctors say the boys are likely sharing more than just sounds.
"There is a quite remarkably rich interchange. They're communicating with each other about each other," said Dr. Kimbrough Oller of University of Memphis. "They're communicating about perhaps the fun of having the conversation. They perhaps imitate what they see conversations look like."
Doctors say 40 percent of multiples have their own unique ways of communicating.
These boys' mother says the animated conversation seen in the video is actually a pretty normal scene around their house.