Training is surprisingly the easier part of raising a standard rattata when you’re used to raising its Alolan variation, actually. Although the two look different, they are actually built similarly and use techniques that are almost identical. The only thing to keep in mind is that standard rattata lack the proficiency with the dark element that its Alolan cousins possess, meaning its strengths and weaknesses to other elements aren’t the same. (Don’t expect your new rattata to be immune to psychic assaults or resistant to other dark-type techniques, for example. On the other hand, yours will handle being bombarded by clefairy much better than your local wild rattata.)

Also note that although your rattata may learn identical techniques and possess similar battle potential, its instincts make it more inclined to exhibit slightly different behavior on the battlefield. You see, the reason why Alolan rattata are the way they are is because of a response to the invasion of small Asian yungoos. As the yungoos is diurnal and prefers the rural and forested environments to which it had been introduced, the local rattata population simply moved to urban areas and became nocturnal in order to avoid their yungoos predators entirely. Because of this change, Alolan rattata have few true predators (urban predators such as spearow, rufflet, eevee, and makuhita are also diurnal, and Alolan meowth prefer hunting sleeping prey), and as such, they’re far tamer and direct with their techniques, ironically enough. That is, Alolan rattata are used to attacking directly and in groups, so they’re bolder and somewhat more reckless. On the other hand, they’re a little more tenacious and resilient, even though their bodies aren’t physically capable of withstanding attacks more than their standard form cousins. It’s just that they’re less likely to let attacks faze them.

By contrast, standard rattata like the one you’ve received have never had the luxury of living in a predator-free environment, and on top of that, typically, rattata’s predators are far more numerous and varied in other regions than in Alola. As such, standard rattata have retained a habit of preferring sneakier attacks. They will often wait for an opportune time and strike as hard as possible, and as raticate, they’re consequently faster and far, far more aggressive. While this seems like a drawback, in actuality, this is part of the reason why rattata is considered a good companion for beginning trainers. (The other reason, of course, is their sheer abundance.) In its rattata stage, these specimens are highly intelligent and eager to work with a trainer who can not only provide them with steady food and protection but also guidance on the battlefield, and if trained into their raticate stage, they retain that sense of loyalty but become formidable battling partners. By contrast, Alolan rattata are harder to rear due to their strictly nocturnal habits, preference for socializing with other Alolan rattata above anything else, and their tamer nature.

That having been said, beyond training, caring for both forms of rattata are also incredibly similar, but you’ll likely find it easier to care for a standard one. This, again, is partly due to its dirunal nature; you won’t have to worry about adjusting your sleep schedule or finding a sturdy enclosure to keep a bored Alolan rattata. It’s also simply because although standard rattata and raticate are extremely grateful for human care, they actually don’t ask for much—meaning they don’t eat as much as Alolan raticate. (Alolan rattata eat less than a standard specimen—which is also important to know—but this is because they horde their food, which is a holdover from their instinct to bring food to raticate in the wild.) Otherwise, offer them the same type of enclosure, the same type of food, the same amount of water, the same type of litter box, even the same type of enrichment as you would normally.

Best of luck, anonymous!