They weren't supposed to survive.

Now 11 years later, conjoined twins Tatiana and Krista Hogan are thriving and enjoying their lives together.

"We didn't know if they were going to survive 24 hours," their mother Felicia Hogan said. "And then 24 hours went by and they survived."

The twins have learned how to swim, and now have started school in the sixth grade. They love running around outside, going camping and like all kids these days, playing video games and watching funny videos on their iPad.

"They're just little people that are here living their lives like the rest of us," Felicia said. "That's how we see them and that's how their siblings see them."

While they are defying limitations by riding a specially-built bike and zooming down hills on a toboggan, their health remains fragile.

Together they deal with Type 1 diabetes and epilepsy. With a daily regimen involving pills, blood tests and insulin injections the twins' care can seem like a juggling act sometimes.

But that doesn't stop them from being normal 11-year-old girls.

The documentary entitled: "Inseparable: Ten Years Joined At The Head," follows the Hogan family for the year leading up to the girls' 10th birthday party.

"For them to actually be here for 10 years is just a blessing," Felicia said. "It just felt so good to see them get to this milestone."

Feel Eachother's Senses

The craniopagus twins, which are twins who are conjoined at the head, are only one in 2.5 million. They share a thalamic bridge that connects their brains. This allows them to see through each-other's eyes, taste what each-other eats and even know one another's thoughts are without speaking.

"The abilities they have that no one else could imagine having are just incredible," Felicia said.

She describes the girls playing together without a word spoken between them and they get up when one decides she wants to do something else.

Not only can the twins see through one another's eyes, they also share emotions and feel it when the other is tickled.

While each controls their own limbs, both twins have the ability to control the other's legs and arms.

Tracking their development since they were only two-years-old, pediatric neurologist Dr. Juliette Hukin describes how rare the girl's condition is.

"They're the only twins that I'm aware of who are alive and remain conjoined with this shared connectivity," Hukin said in a press release.

Now that the girls are older, doctors can better understand their shared bond.

"It was cool to hear from them about how they can see through each others' eyes or move each others' limbs," said the documentary's director and executive producer Judith Pyke. "But just as striking is they get along incredibly well."

Only now as the girls get older can we really understand the extent of their connection.

"Felicia holds up a small stuffed animal in front of Krista's open eyes.

'What am I holding?' she asks Tatiana.

Tatiana, her eyes completely covered, hesitates.

Her mother prompts her. 'Tati, look through your sister's eyes.'

There is a pause, a breath held.

Then Tatiana, eyes covered, somehow floats into her sister's brain: "The Lorax!" she announces."

Like any other siblings, they have moments where they argue and scream at each other.

While the girls may share feelings they have different personalities that some times clash. Krista is the family's jokester. She loves playing pranks and making people laugh. She is also the bigger twin and tends to take charge of the pair.

Tatiana on the other hand, loves to cuddle animals and wants a hug from everyone who comes to the house.

As children, they would try and pull their heads apart when they were fed up with eachother. Their mother always told them that they were stuck, so they would just have to work out their disagreement.

Conjoined During Pregnancy

Felicia found out that the future of her unborn babies was uncertain during her pregnancy. Constantly monitored since birth, the twins went on to be a medical marvel.

'We're just going to take it one day at a time," Felicia said.

And that's exactly what the family did.

With the help of their grandparents, Doug and Louise McKay, the family of five children are able to make things work.

In addition to Tatiana and Krista, Felicia and her husband Brendan are raising three other children, 15-year-old Rosa, 13-year-old Christopher, and 9-year-old Shaylee.

Their grandmother Louise said they continue to defy expectations with the fulfilling lives they lead.

"One doctor said they would be lying on their backs all their lives," Louise said, "but they have surpassed everybody's expectations."

The girls will never be able to be separated or live independent lives because of the way their brains are connected.

"People always ask when will they be separated but they won't be," Louise said. "They have too much wiring going to each other for them ever to be separated."

Share this incredible story with a friend.

Source: Daily Mail / Huffpost / CBC