Like a lot of kids, my six-year-old has a bit of a fascination for what's up his nose. He's an avid miner of green gold. A dedicated booger diver. A nose nugget connoisseur.

And he's not alone. A scientific study of rhinotillexis (the fancy word for nose picking) found that 91% of people will admit they do it, and while most dispose of the pickings in a tissue or hanky, 8% were willing to admit that they picked it and ate it. There's a word for that too - mucophagy. Sounds gross, but some people suggest eating boogers could have some benefits, giving our immune system a boost.

Whether you eat it or not, my kids question is still a good one. What are our boogers actually made of?

To understand what boogers are we need to talk a bit about mucous. Mucous is a slimy mix of salts, enzymes, and proteins, produced by cells lining out nasal passages (and other parts of our bodies).

The mucous produced by our noses has a few roles. First of all, it keeps the inside of our nose moist so it doesn't dry out and crack, which would be rather painful.

It also acts as a protective filter - trapping any tiny particles we breathe in, so they don't make it down into our lungs.

It also contains antibodies, which help to destroy any potential pathogens, like bacteria, that we might inhale.

Most of the time we don't notice this mucous. It's colourless and pretty watery, and mostly it just trickles off down our throats without us noticing.

But when we get sick, or have an allergic reaction, or our nasal passages get irritated, the amount of mucous we produce, and the consistency of the mucous, changes.

The flu and other infections make us produce more mucous, helping our bodies to shed the virus.

We also produce a lot more immune cells when we have an infection, causing mucous to be thicker and stickier.

Thicker mucous can't just run off down into our throats. It gets stuck in our nose, and the tiny hairs that line our noses slowly push it towards the front.

The closer it gets to the outside, the more it dries out.

And the thicker the mucous is, the better it is at trapping dust and other particles.

So what we end up with is globs of mucous mixed with dirt, cells, and other debris. And that's what boogers are made of.

I've told my kid all of this in an effort to dissuade him from eating his.

Unfortunately he seems to be completely un-phased by the whole thing.

But maybe you'll have better luck with your kids.