It might be more than just a gross little habit.
We’ve all seen it: a child absentmindedly digging a finger into their nose, pulling something out, and — without hesitation — popping it into their mouth. For adults, the sight is unpleasant. For kids, it seems completely normal.
So why do children do it? And could there be a reason behind it?
Parents know how common this behavior is. Eating nasal mucus even has a scientific name — mucophagy. Surprisingly, though, there isn’t much research on how widespread it really is.
What we do know is that nose picking isn’t just a children’s thing. Adults do it too. One survey of teenagers in India found that nearly everyone admitted to picking their noses, and several even said they regularly ate what they found.
But when it comes to why, science still doesn’t have clear answers.
It’s Not Just Humans
Interestingly, humans aren’t alone.
Researchers have discovered that at least a dozen primate species show the same behavior.
Evolutionary biologist Anne-Claire Fabre first noticed this while observing an aye-aye — a strange-looking lemur with an unusually long middle finger. She watched it use that finger to dig into its nostrils, pull out mucus, and then lick it off.
“It was funny and disgusting at the same time,” she later said. “But it clearly seemed to enjoy it.”
Further research revealed that gorillas, chimpanzees, macaques, and other primates also pick their noses — and sometimes eat the mucus. Some even use tools or help groom each other.
So this habit might actually have deep evolutionary roots.
Is There a Biological Benefit?
Nasal mucus is mostly water, but it also contains proteins, salts, and sugars. Some scientists wonder whether consuming it might offer small nutritional or biological benefits — similar to how certain animals eat substances to recover leftover nutrients.
Another theory suggests something different.
Because mucus traps dust, bacteria, and viruses before they reach the lungs, eating tiny amounts might expose the body to low doses of germs — potentially helping train the immune system.
However, this idea hasn’t been scientifically proven.
And many experts are skeptical. They argue that the amount of immune material would be too small to matter — and most of it would likely be destroyed during digestion anyway.
Plus, since mucus can carry harmful bacteria, nose picking and mucophagy may increase the risk of spreading infections, especially around vulnerable people.
Or Maybe It’s Just Curiosity
The explanation might be far simpler.
Boogers can feel itchy or uncomfortable, which naturally leads kids to remove them. And curious children often explore the world with their mouths — so tasting might just be part of that exploration.
When a small group of kids were actually asked why they did it, their answers were straightforward:
they liked the texture and taste.
Psychologists also suggest that children don’t yet see the behavior as socially unacceptable. Only later — after being corrected or embarrassed — do they stop doing it openly.
So What’s the Real Answer?
Right now, there’s no definitive explanation.
It might be evolutionary.
It might be biological.
Or it might simply be childhood curiosity.
Until more research is done, the mystery remains.
As Fabre puts it: maybe kids just do it because they like it.
And from a scientific point of view, it might not be quite as strange as we think.
