They actually are proud and tell other people that this man is a real man, he knows how to please a woman." Despite his boasts, several girls I meet in a nearby village express aversion to the ordeal they`ve had to go through. I had to do it for the sake of my parents," one girl, Maria, tells me.
"If I`d refused, my family members could be attacked with diseases - even death - so I was scared." They tell me that all their female friends were made to have sex with a hyena.
It`s clear, given the hyena`s duties, that HIV is a huge risk to the community.
The UN estimates that one in 10 of all Malawians carry the virus, so I ask Aniva if he is HIV-positive.
However, as Ed Butler reports, it has the potential to be the opposite of cleansing - a way of spreading disease.
I meet Eric Aniva in the dusty yard of his three-room shack in Nsanje district in southern Malawi. Wearing a grimy green shirt, and walking with a pronounced limp (he`s been lame in one leg since birth, he says), he greets me enthusiastically. Aniva is by all accounts the pre-eminent "hyena" in this village.
He astounds me by saying that he is - and that he doesn`t mention this to a girl`s parents when they hire him.