Where to catch, #0020
Raticate in Diamond and Pearl: 2 places, levels 50 to 52
4 encounters by area
Places
Route 225 and Sea Route 226
Other games
Also found in 13 other games
Red and Green (Japan)Red and BlueYellowGold and SilverCrystalXDFireRed and LeafGreenPlatinumHeartGold and SoulSilverBlack and WhiteBlack 2 and White 2Ultra Sun and Ultra MoonLet's Go, Pikachu and Eevee