1. A good breeder will have an in depth knowledge of not only the basics of rat husbandry, but the fundamentals of behavior, illness identification, nutrition, medicines, and pre/post natal care.
Not only will a good breeder be aware of proper diet, housing, bedding, and the other basics, they will know rats as a species cover to cover, inside and out. They will understand rat body language, the meaning of their various sounds. They will be able to identify common rat illnesses quickly and efficiently, and will be able to provide their veterinarian with information about the illness and suggest treatment and medicinal dosages. They will have an in depth knowledge of rat nutrition and its specifics pertaining to various life stages and the sexes. A good rat breeder will have an understanding of prenatal care. They will understand the mating process, know how to confirm if a doe is pregnant, know what to add to her diet to ensure the health of her and her unborn offspring, and know when to move her into isolation for the birth. They will know how to tell when labor is progressing normally, and if it isn’t, when it is the right time to step in and involve the aid of a vet. They will have an understanding of the developmental stages of newborn rats and will have the ability to measure whether they are progressing normally. They will know how to sex newborn young, how to evaluate ear type, coat type, and eye color on a newborn, and know how and when to begin the weaning process. They will understand the proper age to separate the sexes, and when young are ready to move on to new homes. In the event that a litter is orphaned, a good breeder will know how to hand raise a litter and have all of the equipment ready before hand.

2. A good breeder will have an understanding of basic rat genetics, and an in depth understanding of the varieties they have chosen to work with.
The ONLY acceptable reason for breeding is to improve upon rats as a species. The only way to effectively do so is to know rat specific genetics, and to learn how to predict the results of potential pairings. Genetics is a full time job. Things are constantly changing - new varieties are created, the specifics of certain color and marking genetics are worked out, things once thought to be true are proven false, etc. A good breeder should also have a very good knowledge of rat standards and how they vary from club to club and country to country- it is impossible to choose the colors, markings, coat types, etc. that you want to work with if you don't first know what’s out there and how to identify it. Without clearly defined goals a breeding program will go nowhere, and without proper genetics knowledge it is nearly impossible for a potential breeder to form goals in a purposeful manner.

3. A good breeder will have the means to financially support all of the rats in their care as well as their potential offspring.
Breeding is expensive. A good breeder will be able to provide adequate housing for their rats, a proper diet, adequate toys and other aspects of environmental stimulation, and proper veterinary care. It is understood that at times, emergencies do occur, and one may be strapped for cash. However, these should be planned for in advance, and putting a few dollars away every month to add up to a substantial vet and supply fund is not difficult. Breeding the RIGHT way costs money, it does not create profit. Good breeders have the insight to plan ahead and ensure that their rats will always be provided for.

4. A good breeder will devote the necessary time to ensure that all of their rats receive proper attention, affection, and free range time.
While there is nothing wrong with having a large breeding colony, a good breeder will ensure that they have some time to devote to EACH of their rats INDIVIDUALLY on a daily basis. As it is not suitable for rats to be strictly caged pets, a good breeder will allow all of their rats at least an hour, preferably more, of free-range time each day. When a large number of rats is involved, it can be difficult to work out a routine that allows each cage of does some time out, and separately, each cage of bucks. A good breeder will understand this and make the necessary accommodations for it.

5. A good rat breeder does not cull, and does not condone the culling of healthy kittens under any circumstances.
Culling is not an acceptable form of population control in any colony, under any circumstances. Neither will a good breeder cull healthy kittens who’s color is "not quite right," or who’s type is bad, or who’s markings are "off." Our rats are first and foremost beloved pets, and a good breeder cherishes each of their animals individually and unconditionally, regardless of whether they’re the "perfect" rat or the ugly duckling who no one wanted to adopt. Culling animals for cosmetic reasons is not acceptable. Culling animals because the litter is too large, or because one is worried that they will not be able to place the entire litter is not something a good breeder will consider. A good breeder accepts responsibility for each and all of the rats that they breed, regardless of circumstances. Part of responsible breeding is knowing when NOT to have a litter; if one is worried about the placement of babies, the good breeder will elect to forego the litter, regardless of their desire to continue.

6. A good breeder will breed primarily to improve the temperament and health of their rats.
While good breeders should have goals in mind when it comes to color, type, and markings, the top priority should always be health and temperament. A good breeder works to create rats who are longer lived, tumor free, and mycoplasmosis resistant. A good breeder will never breed a rat with wonderful color and type if that rat shows aggressive tendencies or a predisposition towards illness. The good breeder breeds to produce healthier, happier, friendlier pets more than to produce the "perfect" show animal, and this will be reflected in the personalities and hardiness of their lines.

7. A good breeder NEVER breeds rats of an unknown background, or rats purchased from a pet store.
Just because your pet store rat appears healthy, friendly, and attractive does not mean it should be bred. Their are many genetic illnesses appearing in rats that can not be discerned by appearance, and the good breeder never risks the safety and health of their line by introducing unknown genes. This is why it is important to have a complete genetic background of each of the rats that you breed. Not only will knowing the carriers involved allow you to make a more accurate prediction of the outcome of a given pairing, a complete background will document any illnesses and instances of aggression in the background of the rat. Breeding pet store rats is a crap shoot, and not one that a good breeder will take a risk on. Good breeders work only with healthy and established lines and from them create their own. Breeders who breed rats with unknown history do a disservice to the animals that they claim to love, and again, the good breeder never does anything that could prove a detriment to rats as a species.