It won't harm the adult cat to eat kitten food, other than consuming the extra calories, but the kitten definitely shouldn't be eating food formulated for adult cats. It would be best to feed them in separate rooms and pick up the food after they've eaten.Jan 3, 2019
Can my kitten eat normal cat food?
Although kittens shouldn't eat adult cat food before they've fully matured, they can begin eating dry kibble and wet kitten food much earlier. By three to four weeks, kittens can begin eating moistened dry kibble or wet food.
Can I feed my kitten adult cat food?
At about 12 months of age, your kitten will reach their full adult size. Your young adult cat no longer needs calorie-dense kitten food to fuel growth and is ready for a diet of adult cat food.
Is it bad if my kitten eats my older cats food?
No it is not dangerous for her health. You can feed them separately to where your kitten will not scavenge your older cat's food. She is taking the older cat's example in what is edible or not by copying her. This is normal.