Stack of parchments in hand - because he had found an older student willing to duplicate his poster for him since he was not skilled enough to do that himself yet - Derf made his way to the hourglasses where he was SURE people would notice them because he was going to innocently take advantage of everyone's competitive nature. BUT IT WAS FOR THEIR OWN GOOD!
It really was all too suspicious. Food and drink in EVERY lesson this term? Suspicious. Which was why he needed to warn the masses and keep everyone safe! Just doing his citrus duty! Wait...that wasn't right...was it? The Hufflepuff stopped what he was doing to scratch his head and think.
CIVIC! Civic duty! Yup. That was what he was doing.
Muggle glue in hand - because a sticking charm still was not within his wheelhouse and he couldn't risk wasting even ONE of his IMPORTANT posters - Derf slathered the Slytherin hourglass with is first and then slapped a poster over it.
Taking a step back to admire his work, and emerald gems completely hidden from sight, the first year gave the poster an approving now and then moved on to the Gryffindor hourglass next.
Glue glue glue...all the glue...SLAP. Poster covering the rubies now!
Gluuuuuuuue all over his own house's hourglass next - which he REALLY made sure there was plenty of because house pride and all - and SLAP, up went another hand drawn poster.
Finishing up with ample glue and Ravenclaw's sapphires out of view, Derf BEAMED at the display. No one was fooling this Hufflepuff, nope!