Kitten play is a sub category of pet play - which is a BDSM practice. There is a lot that goes into it, but generally speaking, Kitten Play is a practice which involves a dom & sub (dominant and submissive). The pet, or in this case kitten, is the submissive, while their master, owner, or guardian is the dominant. A large part of kitten play, and pet play, is feeling like you have someone to take care of you - to rely on. When acting in kitten play, the submissive will meow, bite, scratch, or an other cat like behavior towards the dominant. The dominant will play with their kitten, and reward them for being good. Although, the full system of punishment & reward is a part of this practice.
Someone asked me why I wear a collar, ears, and tail, and I told them it is because I practice KittenPlay.
There is a fiber basedinternet website called Ravelry. There are many, many, many cat threads in the Lazy, Stupid & Godless forum/group. There is one particular person that lives in the Los Angeles area that has many feral momma cats having their kittens in her garage. She traps and spay/neuters the adults, and fosters the babies until they are big enough to be placed in forever homes. There are other members and non members of the group that volunteer to drive a leg of the route to get the kitten(s) to their new home(s) all over the United States, and up to the Canadian border.