Professor Oak's Journal Entry Number 176 - Electric Mice Pokemon as Pets
Like other Pokemon based on animals that are popular as pets in other parts of the world, Pokemon of the Pichu line are likewise popular choices for pets in the Pokemon world, usually in the Pichu and Pikachu morphs.
Pikachu can easily be sexed unlike mice in other parts of the world, because female Pikachu have a heart-shaped indentation in their tails, whereas male Pikachu do not. On the other hand, in order for the Pichu stage to be properly sexed, one must look at the distance between its genitalia and its anus. A female Pichu will have a closer distance, and a male Pichu will have a farther distance.
Pet electric mice obtained in the Pichu stage will often be very young, having been born not too long ago and will usually lack fur and its ears and eyes will usually be closed at first. These are called "pinkies".
Sometimes you might be able to obtain a Pichu with its fur having grown and its ears and eyes open, but this is rare. "Furries" are the name for them.
Electric mice in the Pikachu stage are also common. Pikachu love company, so get at least 2 or 3, but make sure they are all the same gender if you do get multiple, and that they are female. Male Pikachu that are not from the same litter will often fight. Don't put a male and female Pikachu together if you don't want an unexpected litter of Pichu, unless you're intentionally trying to breed.
Pichu (with fur) and Pikachu that are bred to be pets come in all kinds of fur colors, not just the standard yellow fur that wild Pikachu or Pikachu used in battle have.
When a male and female Pikachu that have mated have a litter of Pichu, there are usually five in a litter (though larger litters of up to 12 are not unheard of), the mother usually does most of the upbringing of the Pichu, feeding her milk to her offspring for the first few weeks of their lives as in the wild.
You may notice that a mother Pikachu rubs the bellies of her Pichu children after feeding them. This is to aid the Pichu in passing their solid waste. This behavior is also observed in the wild.
If you adopt any number of Pichu separate from their parents, you'll need to feed them yourself. The first few weeks you'll feed your Pichu Gogoat milk from a paintbrush every few hours (at first mixing it with Pedialyte, then feeding the milk straight or mixed with baby cereal).
It is then up to you to rub the belly(ies) of the Pichu so that they can pass their waste.
After a few weeks, Pichu, whether their mother is present or not, can be weaned off milk and transition to eating solid foods.
There is Pokemon food made especially for electric mice, but Pichu and Pikachu will eat certain human foods too, such as vegetables, peanut butter, stale bread, oats, and cheese. Some Pichu and Pikachu even like ketchup.
As with most Pokemon, and unlike mice in other parts of the world, Pichu and Pikachu are far more resilient than their counterparts in other parts of the world. They are more likely to survive having "the runs" than a mouse in any other part of the world, they can take in sports drinks to counteract any hydration lost.
Also unlike mice in other parts of the world, Pichu and Pikachu, pets or otherwise, can be trained to use human toilets – although this can be true of most Pokemon of appropriate size.
A Pichu and Pikachu's living space must be cleaned properly periodically to avoid serious health problems, although electric mice who have learned to use human toilets see this as less of an issue.
After Pichu have grown up a certain amount of time, males in the litter must be separated from females, such that when they evolve into Pikachu, they don't impregnate their sisters.
After even longer, Pichu will become Pikachu.
The average lifespan of a pet mouse elsewhere in the world is 3 years max. As Pokemon are more resilient, Pichu and Pikachu can live much longer.
As Pichu and Pikachu are mice, they are by definition rodents, and certain teeth will always be growing. They must be provided hard things to chew on constantly to keep them from growing too big.
Pikachu and Pichu can be given tubes and wheels as well to ensure they get plenty of exercise.
On rare occasions, people will give their Pikachu a Thunder Stone and evolve them into a Raichu. This is not very common, as most owners of pet electric mice prefer the earlier stages.
If a Pichu begins to cry, methods to calm a down a human baby will work just as well on a Pichu.
Pikachu who don't use human toilets will often eat their solid waste the first time they produce it to obtain nutrients they didn't get from eating their food. This behavior, also observed in the wild, is also seen among other Pokemon that are based on rodents and lagomorphs (both in captivity and in the wild).
Pet Pichu and Pikachu can either be obtained from traditional pet stores, or from places called electric mouseries, which specifically breed Pichu and Pikachu. The latter option is desired by those who refuse to deal with pet stores.
In other parts of the world, pinky mice are often sold as food for other pets, in particular snakes. The practice of selling baby electric rodents of any species (as well as Azurill) as food for Snake Pokemon has been outlawed for many years, owing to the popularity of these Pokemon.