The reason kittens may be resistant to water is because they are not born with the instinct to like water. Cats are grassland animals. In nature, they rarely come into contact with water and do not need water to survive. So, cats may feel uncomfortable or anxious because they don’t know what to do with a new, unfamiliar object like water. In addition, cats have glands on their skin called "corneal glands" that secrete an oil that makes the cat's skin water-resistant. This may also be one of the reasons why cats don’t like water.
In short, cats' resistance to water may be due to their unfamiliarity with water, or it may be because their skin is water-resistant.
