Test yourself

The Twin Facts Quiz

How well do you know your doubles? This quiz runs across everything on Actual Twin, from how identical twins form to the towns where twins are everywhere, the animals that copy each other and the stars that travel in pairs.

Pick an answer for each question and the page keeps score as you go. Every answer comes with a short explanation, so you will learn something even when you guess wrong.

An orange and black viceroy butterfly with white-spotted wing edges resting on a plant in Oklahoma

A viceroy butterfly, the monarch's lookalike: Thomas Shahan 3, CC BY 2.0

Twelve questions about twins and doubles

1. How do identical twins form?
2. Which famous sporting twins are mirror twins, with one right-handed and one left-handed?
3. Igbo-Ora, nicknamed the Twin Capital of the World, is in which country?
4. Which of these places is NOT famous for an unusually high number of twins?
5. Where is the Twins Days festival held every August?
6. What does a nine-banded armadillo usually give birth to?
7. The bright star Sirius has a faint companion called Sirius B. What kind of star is it?
8. What joins the two Petronas Twin Towers in Kuala Lumpur?
9. The viceroy butterfly looks like the monarch. How do scientists classify that mimicry today?
10. In the 2022 study of unrelated look-alikes, what did many of the closest pairs turn out to share?
11. Dolly the sheep, born in 1996, was the first mammal cloned from what?
12. Mary-Kate and Ashley Olsen shared which role as babies?
Score: 0 / 12

Twin questions people ask

What is the difference between identical and fraternal twins?

Identical twins grow from one fertilized egg that splits in two, so they share almost all of their DNA. Fraternal twins grow from two separate eggs fertilized by two different sperm, so genetically they are like any other brothers and sisters who just happen to share a birthday.

Do identical twins have the same fingerprints?

No. Fingerprints are shaped partly by tiny differences in how each baby touches its surroundings in the womb, so even identical twins end up with their own unique prints.

What makes fraternal twins more likely?

Fraternal twinning is linked to the mother's age, fertility treatments, nutrition and previous births. Twin rates roughly double for mothers over 35.

Can fraternal twins have different fathers?

Yes, although it is rare. When two eggs released in the same cycle are fertilized by sperm from two different men, the twins are half-siblings. Scientists call this heteropaternal superfecundation.

What are mirror image twins?

They are identical twins who look like reflections of each other, for example one right-handed and one left-handed. The pattern is thought to happen when the fertilized egg splits later than usual, around 9 to 12 days, and there is no DNA test that can confirm it.

Sources

Facts on this page were checked against these sources (updated Oct 4, 2026). Spot an error? Email hello@fireempireshop.com.

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