Roof Rats are a Solitary Social Species

Roof Rats are very similar physically and behaviourally to Norway rats. This can be both a blessing and a curse. It’s certainly helpful that their dietary requirements are almost the same, so they can eat the same food. They can also mostly use the same cages, water bottles, hammocks and even toys (although they might abuse them differently.) They are both highly intelligent, curious and playful.

But Norway rats and Roof Rats are different kinds of rats

Apparently, both Norway rats and Roof rats are “social” animals. But…are Roof Rats really social in the way we think they are? How do the social behaviors and needs of a Roof Rat compare to that of a Norway rat?

We don’t know enough about Roof Rat social behavior

Most of the information we have about the social behavior of rats comes from Norway rats. The social behavior of Norway rats, both in the wild and cages, has been extensively researched. Based on this research, and the collective wisdom of the the rat owning community, rules have been developed for keeping Norway rats that are effectively beyond debate at this point: rats are social animals, and they need cage mates to truly be happy. Anyone that keeps solitary rats will be advised that they need to change because they are abusing their unhappy pet, and they need to find it a friend or it will be miserable.

I don’t personally know for sure if all Norway rats want and need to have cage mates. But what I can say with almost 100% certainty is:

Not all Roof Rats actually want to have cage mates

have seen a lot of evidence that Roof rats are often preferentially solitary. And, sometimes, keeping them with cagemates can cause problems that folks used to Norway rats would never experience and would find shocking. For example, it is accepted wisdom that if rats are properly “introduced”, they can eventually bond and form stable, longtime friendships. After which, the owners can relax and be confident that they will happily enjoy each other’s company for the rest of their lives, without any danger that they might one day harm each other. And, with Norway rats, that may well be true.

However, Roof Rats seem to be different. I’ve seen cage mates that have been together for a year or more, apparent “friends”, even littermates that have literally lived together their entire lives, turn on each other overnight without any warning. The only sign would be that one morning one will be injured. Sometimes quite badly. I suspect that some roof rats don’t have the same instinct to form long term social bonds, so they can decide one day they don’t like their former “friend“ and want them gone. Immediately.

This can happen with both males and females. Although it is more common with males. Males will more commonly reject other males, but be OK with females, while females may reject either sex. Once a roof rat starts rejecting cagemates, this change in behavior is often persistent: they may now start to immediately attack other rats in their territory without hesitation as soon as they become aware of them.

A roof rat can cause a surprising amount of injuries very quickly

We’ve tried very hard to find good cage mates for all of our roof rats because we always thought it was “best” for them. And sometimes they do seem to be happy: they groom each other, sleep together, even seem to play together. We let them out, and they follow each other around like they enjoy each other’s company.

I wish I could honestly say that all of our roof rats are happy with cage mates like they are “supposed” to be. But some aren’t, no matter what I think is best for them. And it breaks my heart when they suddenly start hurting their former “friends.” In fact, one of the signs that a male roof rat will be very successful at breeding is that he doesn’t want other males in his cage. Males that can always accept other male cage mates are often very bad at breeding, and sometimes they are ironically bullied (even injured) by females.

Female Roof Rats can be more aggressive than males

So, I think that the desire to hold solitary territory is something instinctive to many Roof Rats, and it is only a “problem” because it is not convenient for their human “owners.” They are perfectly fine with that and may prefer it. We are trying to impose living conditions on them that they would not experience in nature, and not all of them can adapt to it. Some will fight against it, and against the “friends” that we put in their cages.

More research is needed about the social behavior of Roof Rats

We simply do not know enough about the social behavior of Roof Rats, and it is wrong to assume that we can generalize and apply what we know about a different species, Norway rats, to them.

The process of domestication is not just changing a species to suit our purposes: we also need to change our own understanding and expectations to suit the needs of that species. If an animal isn’t behaving as expected, perhaps it’s our expectations that have the problem, not the animal. Some aspects of a species behavior cannot easily be changed. Part of the joy of keeping a companion animal is learning what is unique and special about it, and adapting yourself to that, rather than insisting that the animal adapt itself to you.

We must give our pet Roof Rats what is truly best for them

Roof Rats are different than Norway rats. Sometimes, those differences are annoying and inconvenient, especially if you were expecting them to behave like Norway rats. But it’s not a Roof rat’s “fault” that it is a different species: it just is. As a future pet owner, it’s your job to learn what those differences are before you accept responsibility for that life, and, once you do, to continue to learn and adapt yourself to that animal for as long as it is dependant on you. I can tell you from personal experience that Roof Rats can be wonderful and rewarding companion animals, but you will need to meet them halfway to ensure mutual happiness!