Twins are cool, but there's a whole lot of other interesting things that you probably didn't know about them. So if you'd like to expand on your twinsies trivia, check out this list of amazing facts below:

Twins can have different biological fathers

This one-in-a-million occurrence happened back in 2009, when a woman named Mia Washington gave birth to twins... with two different fathers.  This occurs when two eggs are released instead of one which can then be fertilized by sperm from different partners.

An easy way to tell identical twins apart is by looking at their belly buttons

Belly buttons are basically just scars from the detachment of the umbilical cord. Since they aren’t caused by genetics, that means no two belly buttons are exactly alike.

Identical twins do not have identical finger prints

During weeks 6 to 13 of pregnancy when the twins start to move, how they touch the amniotic sac will eventually influence the unique ridges and lines on their fingers.

Trained sniffer dogs can tell the difference between identical twins

Since odor is affected by outside factors such as food and infections, it means trained German shepherds can easily sniff out the difference between identical twins.

Separated twins can sometimes live eerily similar lives

Jim Lewis and Jim Springer were only four weeks old when they were separated and sent to different adoptive families. But their lives apart shared some truly remarkable similarities: both had dogs named Toy as kids, smoked Salem cigarettes, drove Chevys, and drank Miller Lite. They had also been married twice; first to women named Linda and second to women named Betty.

Women who give birth to twins may live longer

This has to do with the belief that twins are an evolutionary adaptation, where the healthiest of mothers take the chance to pass on double the genes at once.

Tall women are more likely to have twins

One study found that taller women have more insulin-like growth factor (IGF), which is basically a protein that increases a woman’s chance of ovulating. And the more IGF a woman has, the greater the chance that she will become pregnant with twins. Other research has also found that women who gave birth to twins were on average one inch taller than other mothers.

Women who eat a lot of dairy are also more likely to have twins

Just like humans, cows also produce IGF and release it into their milk. One study that compared twin birth rates from vegan and non-vegan mothers discovered that those who consumed dairy were five times more likely to have twins.

Twins interact with each other in the womb

Research done on twins at 14 weeks of gestation showed that they were seen reaching for each other. Four weeks later, the twins in the womb touched each other more often than they touched their own bodies.

'Mirror Image Twins' look like exact reflections of each other

An estimated 25% of identical twins will develop directly facing each other. Traits include one being left-handed while the other is right-handed. They may also have birthmarks on the opposite sides of their bodies.

Some conjoined twins can hear each other’s thoughts and see through each other’s eyes

Krista and Tatiana Hogan were born attached at the head and share a thalamus (the part of the brain that controls physical sensations and motor functions). This apparently allows them to see, hear and also feel what the other one does.

A woman's body will adjust in strange ways after having twins

A mother's chest can heat up or cool down to regulate the temperature while holding her baby on her chest. When it comes to twins, each breast can independently adjust its own temperature to account for each child.

The highest rate of twin births is in Central Africa

Central Africa has more than 18 twins per 1,000 births. It’s especially high in Benin, where 27.9 out of every 1000 births are twins. The lowest number of twin births can be found in Asia and Latin America.

BONUS: Nearly half of twins invent their own languages

Around 40% of twins form their own languages before they learn one that we can understand. Here's an adorable example of what they would sound like...