Cats drool because they feel the fragrance of milk. They produce a chemical called "salm hormone", which causes cats to drool.

Cats step on milk is a mother-opathic behavior. When a kitten feeds milk, it will press the female cat's breasts with two paws to get more milk. When a cat grows up, it will also step on milk when it misses her mother or feels very happy and comfortable.

Some cats will drool when stepping on milk, which is normal, reflecting that cats enjoy themselves very much, feel very happy, and reach the state of selflessness.