Why does my cat suck on my neck and what could be the reason behind this behavior?

Cats may suck on their owner's neck as a comforting behavior, similar to how they would nurse from their mother as kittens. This behavior could be a sign of affection, stress relief, or a way for the cat to seek comfort and security. It is important to observe your cat's overall behavior and consult with a veterinarian if you have concerns about this behavior.