Sex

Breast size is mostly hereditary but also affected by age, diet, pregnancy, menstruation and body weight.

Wearing high heels may strengthen the pelvic muscles, which helps orgasm.

When prairie voles mate, their brain chemistry changes permanently, and they form a strong pair-bond that lasts for the rest of their lives.

People who have just fallen in love have high levels of the neurotransmitter dopamine in their brains. This creates a pleasure rush similar to cocaine!

Sitophiliacs are sexually aroused by food – by eating it or touching it.

La petite mort, or 'the little death', is a French expression used to describe the moment of physical and spiritual release just after orgasm.

Emperor penguins stay faithful to one mate each year, but change partners from year to year – probably because of the chances of finding the same mate within the short breeding season are very low, after walking between 50 and 120 km to the colony's nesting areas.

Male and female emperor penguins stand facing each other for several minutes and appear to bow to each other before intercourse.

9. Complete sexual inactivity may lead to a reduction in penis size.

10.