You (as in the person) don't swarm. Instead, the Pokemon swarm. If you watch TV, sometimes they will announce that a bunch of _____ (a bunch of a certain Pokemon) has been spotted at ______ (a place). That is the swarm Pokemon. Swarm Pokemon are really special. Every day of the week there is a new swarm Pokemon. Catch them all!
Hope this helped! =)
Swarm
you get it when there is a swarm
Get slakoth in a swarm and evolve it.
Swarm occasionally, in front of Fuego Ironworks.
In Pokemon Diamond and Pearl, Phanpy swarms on Route 207.
Swarm
you get it when there is a swarm
You can obtain Swinub from the swarm in Route 217 in Pokemon Pearl.
You can find it during the Swarm.
Get slakoth in a swarm and evolve it.
You can find it in a swarm at Route 217
You can migrate or catch one from a swarm or trade.
Swarm occasionally, in front of Fuego Ironworks.
beldum swinub eletrike skitty lotad nosepass smoochum
In Pokemon Diamond and Pearl, Phanpy swarms on Route 207.
In Pokemon pearl, you get a nosepass through a swarm. You can get a swarm by talking to the little girl in Lucas' house in Sandgem Town
Snubbull appears in Pokemon Pearl on Route 209 as a swarm. To make Pokemon swarms appear you need to have earned the National Pokedex. To easily find out which swarm is active for the day go to Sandgem Town and talk to your Rival's sister.