The twins fight in womb viral video is sure to bring a chuckle to anyone who's ever had a young brother or sister and know a thing or two about sibling rivalry. In a rare glimpse inside a mother's nesting area for her children before birth, two identical twins fight in the womb, kicking each other to get more room.
The video shows the smaller twin starting the fight by kicking the much bigger twin, in an apparent effort to establish his territory. The little feet stomping back and forth doesn't go unnoticed by the older sibling who returns the kicks with one of its own.
And if the little one didn't have enough to worry in the near future when he has to fight his twin for his share of toys and time with mom, he has to first survive the uterus.
Doctors captured the footage was using a technique called "cinematic MRI" which is used to test for a condition in which an identical twin can absorb blood from the other while in the womb. The condition is known as twin-to-twin transfusion syndrome. If that happens, then one baby eventually loses out because it receives less blood.
"We haven't really been able to see before in such real-time complete pictures how twins interact and what this cine lets us do is see their positions in relation to each other and how much space they have, how much space they occupy, and how they might move around and push each other out of the way," Dr. Marisa Taylor-Clarke explained in an interview with New Scientist.
"So that's something that you can see snapshots of on ultrasound and small parts of it, but you don't get the view of the whole room, as it were, the room being the womb."
The cinematic-MRI uses magnetic resonance imaging to piece together moving pictures from within the body. The technology does not use radiation so it is safer for fetuses.
Dr. Marjorie Greenfield, division chief of general obstetrics and gynecology at University Hospitals Case Medical Center in Cleveland, was surprised at the identical twins jostling for more space.
"If you've got two fetuses in the womb, they can't possibly stay in their own space," Greenfield told ABCNews.com. "Twins have been kicking in wombs for millennia. Only now we're able to experience it like this."
It's never too early for sibling rivalry but in this case, it seems the smaller twin is letting his sibling know that if he wants more space in the womb, he has to fight for it.