Cats lick their owners to show affection and acceptance, but the behavior may also result from being orphaned or weaned too early. According to Animal Planet, a mother cat licks her babies to clean them up, but she also does it to show that she cares and to mark them with her scent.
Stress, such as a family move, anxiety due to the addition or loss of another household pet or illness may cause the habit of licking, nibbling or suckling on a human family member. According to Mother Nature News, licking behavior is comforting for a cat. In rare cases, licking becomes uncontrollable. The American Society for the Prevention of Cruelty to Animals defines compulsive behavior as that which a cat has "trouble stopping, even when you try to distract him with another activity." When licking behavior begins in an older cat, hyperthyroidism is a common cause and a veterinary visit is advised.
When licking is especially annoying, consistent behavior modification tactics are useful. To interrupt the cycle of licking, owners should simply move away and leave the room. They can introduce new toys or treats such as catnip, cat grass or a hemp mouse for entertainment and encourage more exercise. Lemon juice is anathema to a feline, so a quick spritz of lemon juice on favorite licking spots is enough to discourage the unwanted behavior.