Pokemon Brilliant Diamond and Shining Pearl Swarms. Swarms are a feature that allows Pokemon that are typically not found in areas to appear there. The locations change every day and can only be found out through the younger sister of your Rival Dawn/Lucas. She will tell you the area and what Pokemon are spawning- these Pokemon, most of the time, can not be found anywhere else in the game and will be the only chance to obtain them besides trading
Pokemon BDSP Swarm Pokemon
Below are the steps needed to allow swarms to begin occurring.
Below is a list of which kinds of Pokemon spawn in swarms and what locations you can find them in. Remember, swarms change daily, so you have to get there fast if you want the Pokemon.