However, you can infer the happiness of your Pokémon through certain actions:
* The heart symbol: When you view your Pokémon's summary, a heart symbol will appear above its head if it's at a high level of happiness. This is the only visual clue you get.
* Certain moves: Some moves, like "Return" and "Frustration," are affected by happiness. If you see a Pokémon using one of these moves, it indicates that it's happy or unhappy, respectively.
* Evolution: Some Pokémon, like Chansey, evolve through happiness. This is a clear sign that your Pokémon is happy.
Here are some ways to increase your Pokémon's happiness:
* Walking with your Pokémon: The more you walk with your Pokémon, the happier it will become.
* Using vitamins: Vitamins, like Carbos, Protein, and Calcium, can help raise happiness.
* Battling with your Pokémon: Winning battles will increase your Pokémon's happiness.
* Giving your Pokémon massages: Talk to the Massage Lady in Veilstone City to increase happiness.
Remember, happiness is an indirect mechanic in Pokémon Diamond, so you'll need to rely on these clues to understand how happy your Pokémon is!