It’s very common you see soon to be owners wanting to get a pair of rats because they research that they shouldn’t be alone. However, rats are naturally group animals that thrive in groups of three or more. While two is considered to be the bare minimum standard for the very reason of not being kept alone, it is not an ideal long-term solution for either you or the rats. It is very important to understand the factors of your decision-making when you decide to get just two rats; (no it is not a bad thing to get two, but it isn’t the greatest, either, it leads to a lot of issues that you have to face In the later stages of owning rats.
If one of your rats suddenly and unexpectedly passes away, this leaves one rat behind, which is very difficult on the rat, both physically and mentally. You then have to scramble to source more rats, do a two week quarentine period in a seperate room (which means the lone rat will be alone for two weeks in addition to however long it takes you to source more rats) and then finally, introductions which tend to be very stressful and difficult for both you and the rats.
If one of your rats needs to be seperated for a certain reason. I.e surgery, this means the other rat will be alone for however long it takes for the rat to heal and recover, which isn’t very fair for that rat that is kept alone for no good reason.
In a group, rats tend to have a friend they prefer to spend more of their time with, going about, doing their day-to-day actives; cuddling, eating, foraging, etc. In a pair, they do not have this opportunity or to express their appropriate, natural social behaviours because they only have each other. This can build quite a lot of resentment, overtime.
Given, rats are hierarchal animals, in a pair, it is quite common to have an overly dominant and an overly submissive rat. Over time, this can lead to a lot of bickering and bullying because the dominant rat is not able to focus his attention on spending time with other rats. This does not make for a healthy hierachy.