Irma Pince is Snape's mother in disguise? AND Filch Squib or Muggle??? then.

[houyhnhnm102]

No: HPFGUIDX 137343

  
> Corgi:
> I think the greatest piece of evidence for determining whether a
person is a squib or muggle is their animals.  Look at Filch.  He's
got a cat that can pratically summon him when she spots students around. 
[...]
> My supportive evidence is the only other squib we're intimate with
in the series, which is Mrs. Figg.  
[..]
 Anyone who has had the opportunity to own a cat knows that the beasts
don't follow orders well.  

houyhnhnm:

My cats do exactly what I tell them and I'm a Muggle :-)

No, really, I think you've made a good argument.  Shucks!

One of the things that's kind of annoyed me in the Harry Potter series
has been the anthropomorphic behavior of non-magical animals.  It took
me until the pensieve seen of Tom Riddle in the orphange to figure out
that--Oh, they're wizards.  That's why they can talk to animals.  Duh!