if by 'swarm' you mean a mass outbreak, then turn on your pokegear to the radio and go to the prof. oak and Mary's talk show. here they wil mention breaking news of an outbreak of a random hard to find Pokemon. the Pokemon will be random and be different every day.
mass outbreaks are according to day, not time. So there is a different mass outbreak every day.
route 203 (mass outbreak).
the places vary. check the radio to find out which Pokemon is appearing where.
A mass outbreak in Pokemon Black and White is when a certain species of Pokemon becomes available temporarily that would not normally be there. Most of these are for the older Pokemon, and only after the National Pokedex is received.
there is no mass outbreak girl in soulsilver or heartgold. That was in pearl diamond and platinum versions. in heart gold and sould silver the mass outbreak is found by listening to Professor Oak's Pokémon Talk on the Pokégear radio in HeartGold and SoulSilver.
if you turn you pokegear onto the music setting and listen to prof. oak and Mary's talk show, they will mention breaking news about certain Pokemon mass outbreaks... the Pokemon that have a mass outbreak will be different every day but there is a chance to have an outbreak of ralts
listen to pokemon talk. wait for an outbreak and go catch it.
if by 'swarm' you mean a mass outbreak, then turn on your pokegear to the radio and go to the prof. oak and Mary's talk show. here they wil mention breaking news of an outbreak of a random hard to find Pokemon. the Pokemon will be random and be different every day.
rare Pokemon
its an outbreak of pokeemon from other regions
mass outbreak
Mass OUTBREAK
It is exactly where you described it. It's on route 9. If you mean specifically how to get the Pokemon, you need to go into a grassy area, cave, or other place where wild Pokemon appear on that route to find the swarm Pokemon.
A "Mass Outbreak" is when many Pokemon show up in a area where they usually not found. Every day go to Dawn's House in Sandgem Town and talk to her little sister, she will tell you what Pokemon and what route for the mass outbreak! Hope This Helps!
mass outbreaks are according to day, not time. So there is a different mass outbreak every day.
A "Mass Outbreak" is when many Pokemon show up in a area where they usually not found. Every day go to Dawn's House in Sandgem Town and talk to her little sister, she will tell you what Pokemon and what route for the mass outbreak!