Mrs. Figg's 'Cat among the Pixies'

[theadimail]

No: HPFGUIDX 93647

Hi,
  All this talk about "cat among pigeons" reminds me that the most 
unexplored part of potterverse is their sayings and idioms. You can 
say they are slight twists on normal muggle idioms but they are a 
delight to read and in they are so many of them in the fifth book. 
I'd been hoping somebody would kind of group them up at a single 
place. I am always noting them down and forgetting them again.
 Like from "Gulpin'gargoyles" to Mrs.Figg's "...dragon as for an 
egg"(can't remember the start of it, sorry.)
  Anyway, one phrase which I didn't understand perfectly was 
Mundungus Fletcher's "keep your hairnet on". Can someone explain 
what that might mean?

bye
adi