Black cats may be superstitious for Friday the 13th, but they're also among the hardest animals to place for adoption year-round. 

Animal care professionals have nicknamed this issue "Black Cat (or dog) Syndrome" because of the number of potential pet owners' subconscious belief that black cats are unlucky and black dogs in literature are often associated with misfortune, reported Gainesville Times. 

The unlucky stigma of black cats is especially potent today, as it's Friday the 13th. This superstition ties to the stories of the Salem witch hunts where people believed that witches would transform themselves into black cats.

Jon Thomas, Porter County Animal Shelter director in Indiana, told NWI Times that this tale still has an effect on the amount of black cats adopted compared to others. 

Despite the unlucky stigmas attached to black cats and dogs, they still deserve to be adopted. 

"The [Porter County Animal] shelter currently has more than 20 perfectly lovable black and black and white cats which are overlooked because of silly superstitions," Thomas told NWI Times. "They need and deserve loving forever homes." 

This weekend, in honor of Friday the 13th, The Porter County Animal Shelter is running a "Lucky Black Cat Adoption Promotion" to hopefully find some black cats forever homes since "these are the cats that are often ignored due to people's superstitions."