Polyjuice potions don't work while you're asleep

[kizor0]

No: HPFGUIDX 114102

> Janet:
> I've been wondering about that for ages!  The Polyjuice Potion has 
to be 
> readministered every single hour.  So there *had* to be times when 
Crouch 
> Jr. was in his own form -- while he was asleep.
> 
> Snape says at some point that "Peeves can't get into my office."  I 
would 
> suggest that the teachers' offices were impenetrable to ghosts in 
general, 
> or one of them might have drifted through one night while Crouch 
Jr. was 
> asleep and noticed that All Was Not As It Seemed.

If Peeves can't get into Snape's office, then it stands to reason 
that there are ways of keeping those of the spectral persuasion out. 
Crouch!Moody, impersonating an impressively paranoid person, could 
easily deploy the lot with minimal eyebrow-raising, and safeguard his 
sleeping space against everyone else as well as he's at it.

- Kizor