The four-year-old “mirror image” twins do everything in precisely opposite ways

The four-year-old twins of the “mirror image” do everything from parting their hair to holding a pen in exactly opposite ways.

Leah and Erin Sullivan, of Inverness, Scotland, are like “two sides of the same coin” according to their mother Zoe, 42.

As Leah separates her hair on the left, Erin separates hers on the right and they both favor opposite hands for throwing or writing.

The couple sleeps even in the same position, but on different sides.

They are “mirror image twins”: a little-known phenomenon that means identical siblings are asymmetrical in their appearance and how they move or interact.

The phenomenon is believed to affect up to a quarter of identical twins and Zoe found out that her twins were affected last year.

Mother Zoe, who stays at home, said, “If their hair has grown out, it’s very hard to tell!”

“Leah’s hair grew faster, but it wasn’t until two-and-a-half years that the bangs started to grow and I realized they were parting in different directions.”

“It didn’t matter what you did, like trying to separate it from the middle or the other side, and it’s really the only way to distinguish them!

That’s when we realized they were mirror twins. Erin thinks she could be left-handed, but Leah is definitely right-handed.

“After noticing it, I looked it up on the internet. It can be really extreme.”

He said Leah is usually left in the photos, with Erin on the right and walking with opposite dominant feet.

And when they face each other, it looks exactly like they are looking in the mirror.

Her nursery also uses her unique hairstyles to differentiate, but there could still be more symmetries that are revealed as the girls grow.

Zoe added: “They are totally different in their personality. Almost like different faces of the same coin.

‘All the personalities that Leah has, Erin doesn’t, and vice versa.

“Erin is very straight (what you see is what you get), but Leah is more cheeky and vice versa!

“You see a lot of personality-like twins, but with them it’s like a person splits in two.

“Leah has a very good sense of humor, but Erin doesn’t understand. She’s much more serious.”

Identical twins are the result of a single fertilized egg that divides into two embryos between four and eight days after conception.

Mirror twins are believed to be the result of egg splitting even later, between nine and twelve days, although this has never been proven.

Eleven-year-old mother Zoe said, “The twins run to the family next to me because my grandfather was a twin and I have twin aunts, but they were still a little shocking!

“I also had a couple of non-identical twins four years ago and I think part of me knew deep down that they would be twins, but I was more surprised that they were identical.”

The girls were born prematurely at 27 weeks on January 25, 2016, on the eighth anniversary of their first group of twins.

Leah weighed 3 pounds 4 oz and Erin 2 pounds 6 oz at birth and was hospitalized for six and ten weeks respectively.

Leah suffered a collapsed lung, Erin contracted sepsis and had extra fluid in her brain and both girls had heart murmurs.

At one time Erin weighed only 810 g, and with seven other children at home at the time, both parents were exhausted.

Zoe, who is married to the girls’ father Ben, said: “It was a very traumatic time.

“Ben was doing half a day, so I could take care of the other kids while I was in the hospital and then we would change them. I have no idea how we did it!”

Zoe admitted that when they were babies it was almost impossible to distinguish girls.