The reason why cats like to lick people's hands may be because it helps them clean their skin and hair, or it may be because they find it fun. Licking is a common way for cats to clean themselves, and they learn this action when they are young. Cats lick their skin and fur with their tongues to help remove dust, dander, and other debris.
In addition, cats may also lick human hands to show their affection or closeness to you. Cats will often lick things or people they like, either because they find the smell of those things or people attractive or because they find licking them brings pleasure. If you don't want your cat to lick your hands, you can try offering him other cleaning options, such as placing a dish of detergent or letting him lick a wet towel. You can also try to provide him with more toys and cleaning tools, such as a self-rotating cleaner or a wall-mounted cloth cleaner so that he can lick and clean himself on these items.
