Sex is, of course, what makes the world go round. Without it, neither you nor I would be here today, and as such, it’s something that most people strive for in life. However, things aren’t always so simple. Different people have different desires, libidos, and sexualities. What’s more, did you know that there are some people who may not experience any kind of arousal at all? Take a look below for 30 interesting and crazy facts about sex.

1. In the animal kingdom sex is, of course, mainly a reproductive effort! However, humans are one of few species that have evolved to derive pleasure from it.

2. The physical activity of sex is usually contained within the same species, however, some species mix! For example, this can occur when horses and donkeys mate to produce a mule.

3. When a tiger and lion mate the offspring is either called a ‘liger’ or a ‘tigon’! The name it receives depends on which animal was the father, and which was the mother.

4. ‘Misdirected mating’ or ‘reproductive interference’ are terms given to animals who mate with different species. These include seals, some types of dolphin, some birds, and also some big cats.

5. Aristotle believed that heat during sexual intercourse determined the sex of a baby. The ‘hotter the passion’, the more likely a baby would be male! He advised elderly men to impregnate women in summer if they wished to produce an heir.

6. Human embryos develop genitals at approximately 7 weeks.

7. In birds, the sex of offspring is determined by the chromosomes known as ‘z’ and ‘w’.

8. Plants have sexual parts! Their genitalia are usually to be found in the center of flowers.

9. Most plants and flowers are actually bisexual, as well as hermaphroditic. They have both male and female parts for procreation.

10. ‘Test tube babies’ are those who conceived outside the womb, usually in a laboratory condition. Couples who are unable to conceive through sex may choose this method to have their own children.

11. Did you know that sperm has measurable speed? It is thought that the average speed of sperm travelling during ejaculation can be as much as 28 miles per hour. How do you even measure that?

12. Artificial insemination has been carried out in animals other than humans for decades. For example, endangered species, perhaps with less opportunity for sex, can continue to grow through artificial means.

13. Sex has largely been seen as a positive act going back millennia. However, it is only with the rise of certain strict religious scripture, such as that which is available in the Bible, where a more negative view of intercourse has become common.

14. It’s thought that only around 4% of the US population identifies as gay, bisexual, or lesbian.

15. Male Scorpions ejaculate on the ground and pull the female Scorpion into a position so her sex organs touch the floor.

16. It is common for some animals, after sex, to eat their partners.

17. Studies show that having sex can lead to better self-esteem. This means that some people feel they are more attractive and perhaps even more powerful after coitus.

18. It’s thought that the more regular the intercourse, the better quality a man’s sperm might be. This is actually a common suggestion for couples who are struggling to conceive children.

19. Studies also appear to suggest that oxytocin released during sex may help to relieve pain! Specifically, it is women who stand to benefit from this natural pain relief the most.

20. There is such a thing as post-sex depression. This is a condition called post-coital dysphoria. Some people note that they can experience anger and severe feelings of sadness after having sex or masturbating.

21. Many people are asexual or have no desire to have intercourse. Up to 3% of the global population have no sexual desires whatsoever.

22. Dr. Kellogg, who is famous for creating corn flakes, is said to have developed his cereal to help decrease people’s inclinations to masturbate. He was a staunch anti-masturbation activist.

23. Statistics seem to show that people who are married tend to masturbate more than those who live on their own.

24. On average, it is said that men have around 11 erections per day. They can even experience a similar number during their sleep.

25. Sexual reproduction is said to have existed for more than 30 million years, and it is likely the Funisia dorothea that was the first species to experience it.

26. It’s thought that men who do more housework tend to be more sexually active, on the whole.

27. ‘Having a headache’ is not actually the by-line for refusing sex that it once might have been. In fact, some people who have migraines actually report higher feelings of sexual arousal and desire.

28. Vibrators were actually developed as medical aids, at least initially! Believe it or not, they were initially used to treat ‘female hysteria’ in the 1800s. The very first vibrators – weirdly enough – used to run on steam.

29. Low libido is something that both genders can suffer from. This can lead to some partners struggling to meet each other’s needs. This is why communication is so important!

30. Believe it or not, the egg chooses the sperm – and it’s not necessarily the winner of the race!