CHAPDISC: HBP1, The Other Minister

[Hagrid]

No: HPFGUIDX 141999

> 5. Fudge says the dementors are breeding, which is causing the
> gloomy weather throughout England. We know prior to this the
> dementors were guarding Azkaban and working with the Ministry, yet
> there was no chilly mist covering the land until now. Why weren't
> they breeding before? Ministry controls? An agreement?

Meri: Maybe dementors can only breed if given proper scope for their
powers, which is what LV is giving them.

Ceridwen:
Maybe Ministry controls. Allowing only limited breeding, perhaps?
Or, it could be that they were too restricted on Azkaban to breed
much beyond their population. Or, they're like cougars, territorial,
and to have offspring, they need to have a certain amount of space.
Or, they did breed, but only in remote places near Azkaban (or on it,
how would that be for affecting prisoners?), and the only reason it's
noticeable now is because they're breeding closer to populated
centers.

justcarol67"
Evidently the MoM had some degree of control over them and they were
confined to Azkaban. Voldemort has evidently given them new
privileges--or even free rein.

~aussie~
A good indication of Dementors and other weird beings we find within 
JKR's pages is found in "Fantastic Beasts and Where To Find Them". 
Many of the most dangerous "Beasts" were bred by wizards for 
guarding purposes from other creatures. The Dementors seems to have 
such a back ground. 

Ref Lethifold .... and I quote ....

LETHIFOLD 
(also known as Living Shroud) M.O.M. Classification: XXXXX
The Lethifold is a mercifully rare creature found solely in tropical 
climates. It resembles a black cloak perhaps half an inch thick 
(thicker if it has recently killed and digested a victim) which 
glides along the ground at night. 

... the Patronus is the only spell known to repel the Lethifold. 
Since it generally attacks the sleeping, though, its victims rarely 
have a chance to use any magic against it. Once its prey has been 
successfully suffocated, the Lethifold digests its food there and 
then in their bed. It then exits the house slightly thicker and 
fatter than before, leaving no trace of itself or its victim behind.