Subliminal kitty messages? " You are getting very sleepy' is not a command when said to a cat; it is the eternal truth.
Cats are not social animals. They do not have to live in groups.
Kittens on the other hand like playing, eating and sleeping with theirfellow kittens.
They are usually friendly and playful unlike when they mature as cats who may prefer solitary living with their humans as companions.