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We recently explored the mysterious and fascinating properties of earwax – from how it can trace ancient human migration patterns, to its use as an early lip balm. It proved to be a really popular story – perhaps more so than we anticipated for a rather disgusting topic.

So, in light of this puzzling but undeniably strong demand for revolting scientific facts, here’s what we’ve learnt about the rest of your body’s sticky products and smelly emissions, plucked from the BBC Future archive. You asked for it.

Flatulence on planes may not seem like a topic that would interest a scientist...but it has been studied (Credit: Thinkstock)

Everyone does it, it’s not just you. Flying makes us fart more. The change of pressure causes abdominal bloating as the small amounts of air inside us expand, and there’s only one way it’s going to go.

This problem is a serious issue for pilots – 60% of whom report regular issues with bloating. And, at one point, Nasa was concerned that astronauts’ flatulence would be lethal in the confines of a cabin: a 1969 paper highlighted the risk of a fireball resulting from the high concentration of human gas in spacecraft.

Find out more: Why do we fart more on planes?

Why exactly do people pick their noses? (Credit: Getty Images)

It’s disgusting, potentially harmful and surprisingly common. Rhinotillexomania – or nose picking – is something that 91% of us confess to doing. Why? Probably because many of us are too lazy to reach for a tissue.

For some, it can become a compulsive behaviour. One 53-year-old woman suffered chronic nose picking so bad that she not only perforated her nasal septum, but also picked a hole into her sinus.

For most, though, occasional nose picking will probably not lead to any pathological issues.

Find out more: Why do we pick our nose?

Why do some people collect belly button fluff, but others don't? (Credit: Getty Images)

Not all of us collect fluff in our navels. Less hairy-bellied people will collect less lint, as it’s the hairs around our belly buttons that channel the fluff into the depression.

But before you pick it out, fluff might actually help keep our belly buttons cleaner by collecting bacteria as it forms.

Find out more: The curious truth about belly button fluff

The ears have it

Returning to the sticky substance that led us on this journey, earwax comes in two types: wet or dry, and this is genetically determined. It’s all due to a single letter difference on a solitary gene, but the two resulting types of earwax even have a different smell. Read the whole article: The mysterious properties of the wax in your ear

Some of the things that leak out of our bodies in sweat might surprise you too. For example, 7% of someone’s daily excretion of urea is in their sweat. But, sweat might also be an important tool for communication. The scent of people in strong emotional states, like heightened fear, can also influence the people around them – and this might have been something our ancestors took advantage of. Explore more of the olfactory clues given away in our sweat: What our perspiration reveals about us

The sneezing reflex caused by light is known as 'Achoo', which stands for Autosomal Dominant Compelling Helio-opthalmic Outburst (Credit: Science Photo Library)

Sneezing when being exposed to a bright light is not only a recognised phenomenon, but a fairly common condition and one we’ve known about for a long time. The reflex – named Autosomal Dominant Compelling Helio-opthalmic Outburst (or, pleasingly, Achoo) – might have been first recognised as far back as the third century BC.

Not everyone is affected, but for those that do suffer the affliction, it can prove quite dangerous in certain situations, like driving through dark tunnels. Find out if you display any of the other symptoms: Why looking at the light makes us sneeze

Finally, possibly the stickiest of all the secretions we’ve looked at, eye gunk is perhaps the most puzzling, too. It certainly seems to be the most pointless to the untrained eye. But meibum – to give eye goo its correct name – is finely tuned to the needs of the mammalian body.

For a start, the viscous, oily fluid prevents tears from constantly rolling down our cheeks, keeping our eyes appropriately hydrated. Read more here: Why do we get sleep in our eyes?


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