Being blind, Dementors sense and feed on the positive emotions, happiness and good memories of human beings, forcing them to relive their worst memories. The very presence of a Dementor makes the surrounding atmosphere grow cold and dark, and the effects are cumulative with the number of Dementors present. Despite their attachment to human emotion, Dementors seem to have difficulty distinguishing one human from another, as demonstrated by Barty Crouch Jr's escape from Azkaban, wherein they could detect no emotional/mental difference between the younger Crouch and his mother. They also have difficulty sensing animals because their feelings are more primitive than human emotions; this particular weakness enabled Sirius Black to escape from Azkaban in Animagus form. In addition to feeding on positive emotions, Dementors can perform the Dementor's Kiss, where the Dementor latches its mouth onto a victim's and sucks out the person's soul. The victim is left as an empty shell, incapable of thought and with no possibility of recovery. It is believed that existing after a Dementor's Kiss is worse than death. The Ministry of Magic occasionally uses this as a punishment, such as on Barty Crouch Jr. Because they are immortal, very few methods exist to repel a Dementor; one way to shield oneself from Dementors is to use the Patronus Charm to drive them away. Chocolate is an effective first aid to mild cases of contact. Dementors are invisible to Muggles, but affect them in the same way. While at least one Squib in the series has claimed to see a Dementor, Rowling has stated that this was a lie and that Arabella Figg noticed it because of the effect it had on her.[8] Rowling has likened the effect of a Dementor to the human ailment known as depression, which the author has herself experienced.[9] She describes it as "that absence of being able to envisage that you will ever be cheerful again. The absence of hope. That very deadened feeling, which is so very different from feeling sad."[10]

Harry first encounters Dementors during the beginning of his third year of school, when they are sent to guard Hogwarts against Sirius Black, who has recently escaped Azkaban. Harry, whenever he gets near one, is forced to relive his worst memory: hearing the last moments of his parents' lives before they are murdered by Voldemort, which begins with Harry hearing his mother screaming. To overcome the Dementors, Harry asks Remus Lupin for assistance. Lupin teaches Harry the Patronus Charm, albeit with some difficulty. In Harry Potter and the Order of the Phoenix, Harry and his cousin Dudley Dursley are ambushed by two Dementors sent secretly and illegally by Dolores Umbridge. At the end of Harry Potter and the Order of the Phoenix, the Dementors of Azkaban stage a mass revolt against their employers to join Voldemort, as he can provide them with more humans to feast upon. In Harry Potter and the Deathly Hallows the Ministry, under the control of Voldemort, uses Dementors to punish those who are Muggle born for no other reason than because Voldemort hated Muggles and Muggle-borns. The Dementors also take part on Voldemort's side during the Battle of Hogwarts. After the appointment of Kingsley Shacklebolt to the position of Minister, Dementors are removed from Azkaban, and the Ministry contains them by limiting their numbers

დამატებულია (11.05.2009, 14:27)
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