Most of the time
It stays up your nose,
Nicely hidden away,
But when you catch a cold,
That's when it flows,
That's when it comes out to play!

Well.

Some call it 'mucus',
Those in the know,
Those who think they've
A bit of a brain.
But its name doesn't matter,
When you sneeze,
It still goes splatter!
And when you sniff,
It still flies back up the same.

It can be a little bit green,
If you know what I mean,
But also yellow,
And, yes, sometimes brown,
And when you get the flu,
It's really nothing new
To feel that, in snot,
You might drown.

Often it runs just like water,
Sometimes it's more like glue,
But when it starts to get a crust
You can usually trust
Someone to flick it at you!

Small and round and crusty,
Sat just on your finger's tip,
Deadlier than any missile,
And launched with a simple flick.

But whether it runs,
Or whether it flows,
Or whether it hangs
Off the end of your nose,
Or whether it makes
You breathe like a seal,
PLEASE don't use the crusty ones
As your next meal!