Yes, of course they can swarm more than once. To know when a swarm is happening, talk to your rival's sister or watch TV. If a swarm is happening, a News Alert will show up on the TV when you interact with it.
The Swarm Pokemon are post-Elite Four Pokemon which appear in random Routes and Caves. These Pokemon are rare and difficult to obtain otherwise. Once the day is over, another Swarm Pokemon will appear somewhere else.
once you get the national dex Pokemon will swarm and it will swarm north of the fight aerea
After you beat the Elite Four and recieve the National Pokedex, Dawn's sister tells you where a swarm of pokemon are. These are usually Pokemon from different generations of games. However, you can only talk to her once a day.
no
Swarms are another feature that have been retained in the change of Pokemon diamond & pearl to platinum. Swarms remain the same and require you to have the National Pokedex. Once you do, go see your rivals sister in Sandgem Town. She will tell you where the swarm the swarm Pokemon is and what Pokemon is there. Once known, you can go there and find out. The swarms change every day so always check so that you can get the Pokemon you want.The Swarming Pokemon are:Doduo,Zigzagoon, Cubone, Lsrvitar, Phanpy, Dunsparce, Snubbull, spoink, Drowzee, Delibird, Voltorb, Farfetch'd, Skitty, Natu, Makuhita, Krabby, spinda, Pinsir, Corsola, Electrike and slakoth.
once games completed and nationl dex talk to dawns sister she will tell you that there is a swarm of skitty/spinda or ditto on various routes
Play Runescape and get duhhh easy question.
Yanma can sometimes be found on Pokemon Diamond, Pearl, and Platinum in the Great Marsh in Pastoria City. You could also catch and evolve a yanma from HeartGold or SoulSilver (found on Route 35 during a swarm) and trade it over to your Pokemon Diamond version. Yanma evolves once it learns AncientPower. You can obtain yanma on Firered or Leafgreen version in Ruin valley and migrate it over to your Pokemon Diamond, Pearl, or Platinum version have it learn AncientPower...and there you have it, you're very own yanmega.
No, unfortunately not
Yes you can. Mainly once you beat the elite four, but other more common Pokemon can be found that are not exclusive to the Sinnoh region.
No. In Pokemon Diamond you can only catch Dialga once but you MIGHT have a second chance after beating the Pokemon League at least once.
You can breed Lucario with Ditto or trade for more, but you can't actually catch any more.