I've heard that shelters won't adopt out any black cats in October. To prevent someone using a black cat as a party prop or worse at a Halloween party.
I have heard of this too. I have a black cat myself but he was adopted in May two years ago. I had a black cat that ran out of the house on me years ago on Halloween during the day when we were leaving to go to a wedding. I was really worried about something happening to her. Luckily one of my neighbors who used to cat sit for me was home. I knocked on her door asking for help because we had to leave. My neighbor was able to find my cat and kept her inside her apartment until we got home. I was lucky she found my cat within a couple of hours. She had decided to hide under the stairs when she ran out. My neighbor lured her out with wet food and brought her inside. We used to hang out on our deck and the cats would run back and forth chasing each other in both apartments. The cats were friends. One time one of my cats was playing with her cat and he decided to take a nap on her bed with her cat. All our cats were fixed. We let the cats hang out together and enjoy their nap. She brought my cat back over when he woke up and was looking for food.
Here in our town they tell people to be sure and keep their Black kitties, and their black doggies up during this time because people who practice Black Magic and Witchery will pick them up to do animal sacrifices on Halloween Night. This is just one of many reasons why I was so glad to finally get my Sammy away from his irresponsible owner who was letting him run loose outside. I've got 3 Black kitties who all will be safe and sound inside my house this Halloween.