Damage Types (rats)-
Angel Explosive/Kinetic
Amarr/Ammatar Navy - EM/Thermal
Blood Raiders EM/Thermal
Caldari Navy Thermal/Kinetic
Centis/Corpus EM/Thermal
Dark Blood EM/Thermal
Gallente Navy Kinetic/Thermal
Guristas/Mordus Thermal/Kinetic
Khanid EM/Thermal
Mercenary Thermal/EM + Kinetic missiles
Minmatar Navy Explosive/Kinetic
Rogue Drone Kinetic/Thermal
Rogue Pirate EM/Explosive/Kinetic
Sansha EM/Thermal
Serpentis Kinetic/Thermal

and i have what each rat type is weakest too:
Main Damage type to shoot at the enemy:
Guristas - Kinetic
Serpentis - Thermal
Mordus - Thermal & Kinetic
Blood - Thermal/EM
Sansha - Thermal
Mercenary - Thermal
Rogue Drones - EM