Keyboards in a computer lab with very sticky keys that make you...

...wonder exactly what made them so sticky in the first place.

You look closer, tap the enter key experimentally and realize that a dried brownish substance is making the keys all gluey.
Bah! Spilt Coffee!

You whip out your handy Leatherman and pry off a couple of keys to investigate further and you realize that there's a lot more liquid underneath; congealed with bits of hair.
It's fresher and more red somehow. Red. Like blood. And you realize your mistake. Too late.

WHUMP!