Kittens can eat egg yolks in moderation, but the following points should be noted:
1. Moderation is key: Egg yolks are a nutrient-rich food, containing protein, fat, vitamins, and minerals. However, kittens' digestive systems may be sensitive to high-fat foods, and excessive fat intake can lead to indigestion or diarrhea. Therefore, moderation in egg yolk intake is important, and it's best to determine the appropriate amount for kittens under the guidance of a veterinarian.
2. Ensure safety and freshness: Make sure to use fresh egg yolks and look for any off-odors or signs of spoilage. Avoid feeding kittens egg yolk products containing additives, flavorings, or other harmful substances.

3. Gradual Introduction: If you want to add egg yolk to your kitten's diet, it's recommended to introduce it gradually. Initially, you can mash the egg yolk or mix it into the kitten's wet food and observe for any digestive problems or allergic reactions. If the kitten doesn't react adversely to the egg yolk, you can gradually introduce more of it.
4. Pay attention to a balanced diet: Egg yolks alone cannot provide kittens with the complete and balanced nutrition they need. Kittens require protein, fat, vitamins, and minerals from a variety of foods. Therefore, egg yolks should be part of their overall diet and combined with other kitten-appropriate foods to ensure they receive complete nutrition.
Most importantly, consult a veterinarian before introducing new foods to your kitten. A veterinarian can provide appropriate advice and guidance based on the kitten's specific needs and nutritional requirements.