The Dementors feed off of despair. Voldemort's army spreads it, allowing the dementors to breed. The Dementors take care of the
And the only reason the Dementors choose to follow Voldemort is because he frees them from their duty to Azkaban, allowing them access to the richer pickings on the mainland.
They're Team Voldemort
For a long while there was a uncomfortable allegiance between the Dementors and the British Ministry of Magic that employed them, but once the opportunity to really feed their appetites presented itself, they unsurprisingly defected and joined Voldemort.
Albus Dumbledore was one who had long disapproved of the use of Dementors as guards, not only because of the inhumane treatment of the prisoners in their power, but because he foresaw the possible shift in loyalties of such Dark creatures.
So it is possible that in case of Voldemort, they didn't try to harm him in any way, considering him their friend, and thus the normal ill affects of Dementor's presence wasn't much of problem for Voldemort. Finally, Voldemort had promised them plenty of humans to feast on in return of their help and service.
The Dementor is simply unable to perform the kiss on a wizard who has a Horcrux. Voldemort is unaffected and has a good laugh at the silly Dementor.
Gryffindors are brave. The Dementors pull out the worst memories you have. Harry's worst memories involve his mother's death. Voldemort is just a wizard (okay, a very powerful evil wizard).
Ekrizdis is a minor yet pivotal antagonist in the Harry Potter universe. He was an immensely evil wizard who lived in the 15th century in medieval Britain, it is believed he was either the creator of the Dementors or that his insane experiments and torture caused the Dementors to first manifest.
In Prisoner of Azkaban, Harry's reaction to the Dementors is a direct representation of the experience of depression. Dementors are guards for the prison, Azkaban, and come to guard Hogwarts when there is a risk of an escaped prisoner.
Rowling has revealed that the Dementors were inspired by her own feelings of depression.
The "most faithful servant" is Barty Crouch Jr., who has already been in place at Hogwarts working for Voldemort. The three dead include Evan Rosier, Wilkes, and Regulus Black.
One of the most powerful defensive charms known to wizardkind, the Patronus can also be used as a messenger between wizards. As a pure, protective magical concentration of happiness and hope (the recollection of a single talisman memory is essential in its creation) it is the only spell effective against Dementors.
Horcrux has no feelings, if a dementor go near to a Horcrux, they will not bother, right because it's just a thing not a human, a thing without any feeling and happiness.
Voldemort Never Figured Out Snape Was A Spy
He openly despised some of his Death Eaters, even the loyal ones like Luscious Malfoy. However, there were a select few that had his trust, and whom he treated with respect. This included Bellatrix Lestrange and Severus Snape.
After Voldemort's downfall on the fateful night of Halloween in 1981, many Death Eaters are captured, but Lucius avoids being imprisoned by claiming that he was under the Imperius Curse throughout the war. He manages to retain his position among the social elite, but still remains a power-hungry bigot.
Every time Harry is confronted with a Dementor, he hears the screams of his mother as she is murdered by Lord Voldemort. A horrific memory to hear... He hears this moment because Dementors feed upon happiness and cause depression and despair in anyone near them. They make people relive their worst memories.
Behind the scenes. It is possible that chocolate is used to ward off the effects following meeting a Dementor as it has chemicals inside it that stimulate the release of endorphins, which are chemicals produced by the body to combat stress and pain; often leading to feeling of increased happiness.
He teaches Harry to recognise the Dementors for what they are - greedy, soulless, evil creatures - while also giving him the confidence and knowledge to fight back, by harnessing his happiest memories, another piece of advice I'll be following from now on.
A theory posted on Reddit suggests Dementors were drawn to Harry because they could sense the piece of Voldemort's soul living in him. Harry is an “accidental horcrux”, created when the killing curse casted by Voldemort backfired, fragmented his soul, and sent a piece of it to Harry's body.
It is clarified that they have genders and reproduce asexually. The Dementors refer to themselves as Mind People, due to their telepathic ability, which goes farther than the ability to suck out happy memories and allows them to communicate with humans or with each other without speaking, which they are unable to do.
Reproduction. Dementors breed by surrounding themselves with large amounts of a special fog which they exude. New individuals, already fully formed, will gradually congregate from the mist. Dementors usually breed in large groups.
Speaking of joy-thieves, she might have preferred to cloak herself in pink and fill her office with fluffy kittens, but Dolores Jane Umbridge was every bit as dark as the villainous figures she liked to surround herself with. Indeed, she was the one who sent Dementors to attack Harry in Little Whinging.
Voldemort's greatest fear is death and as a result a boggart takes the form of his own corpse. It is unsurprising that this is Voldemort's biggest fear. After all, he did split his soul up encasing it in various horcruxes just so to keep himself from dying.
Dumbledore - Ariana Dumbledore
He fears the lifeless body of Ariana Dumbledore, his sister, with who he associates his biggest regrets.
To Be Confronted By A Dementor
The confrontation with a Dementor on the Hogwarts Express made Harry realize that this creature was his deepest fear in a corporeal form. The Dementors made his inner feelings of hurt and abandonment come to life, along with bringing back his worst memories.