© Angela Horn, 1998
Rats are social animals, gaining much enjoyment and stimulation from each other's company. They live in large family groups in the wild, so in captivity they live a more natural life if kept in pairs or more. They are not like the Syrian hamster, which is a naturally solitary animal, and hence is kept alone as a pet.
Rats living in groups can have fun chasing each other around, grooming each other, sleeping in a heap, playing tug-of-war with food, wrestling, sometimes scrapping, communicating, forming friendships, and generally acting like schoolchildren at playtime. If one rat wants peace and quiet, it can simply go off and sleep alone; if it wants company, friends are always at hand. It has many more options than the single rat, who can only sleep, or sit and wait for human attention. Rats living in groups have more full and varied lives than any single rat.
Zoos and laboratories nowadays focus on 'environmental enrichment' - ways in which captive animals can be given more interesting lives by mimicking aspects of their wild relatives' lifestyles. The most important element of enrichment is allowing the animals to live in similar social groups to those found in the wild, since social animals have evolved to flourish in the company of others of their own kind. They are not 'designed' to live happily alone.
Some common questions and comments about the social needs of pet rats are addressed below.
Rats will not usually pine away and die simply from being kept alone - so if you are concerned simply with what rats need to stay alive, you can keep them alone. However, it is not fair to think only of what our pets need to keep them alive. We should also think about what they want to give them happy lives. Rats living in pairs have more full and interesting lives than single rats, because many more experiences are available for them. Keeping rats in pairs is a very easy way to give your pets better lives - elaborate toys and cages are great if you can provide them, but the first and best toy for a rat is always another rat. Many laboratories now refuse to keep rats alone, because it is considered unfair; surely pet owners should be at least as concerned as laboratory staff to keep their animals happy.
A single rat is often happy, whenever you are playing with it. But when you are asleep, or out at work or school, or simply going shopping, the single rat can get bored and lonely. It has nothing to do whenever you are not around. Unless your rat is with you literally 24 hours a day, it is inevitable that it will be bored sometimes.
Rats do not sleep throughout the night like us - they wake and sleep at intervals throughout the day and night. They are often particularly playful during the night, when most humans are asleep.
Even if you were the rat's perfect human - never apart from it, and sleeping only for an hour or so at a time - you could not provide it with the same sort of companionship as another rat, simply because you are a very different species. You would not, for example, communicate with it, or (presumably!) groom it with your teeth the way another rat would.
No - anyone who keeps several well-socialized rats will tell you that this is nonsense. If you doubt this, I suggest that you visit a rat show or an experienced breeder, and ask to meet some rats which live with companions of their own species.
The way to make rats devoted to you is to handle them frequently - several times a day, beginning as soon as you get the rats - and to treat them gently, and offer them treats. Rats will bond with you because they enjoy your company, not because they are desperate for company of any kind.
Depriving a rat of the company of its own kind is likely to simply make it unhappy. It is a very unkind way to treat pets - imagine what we would think of a parent who refused to let her child meet other children, 'so that she will love me more'.
Single rats may develop behavioural problems - becoming introverted and hiding away, or getting clingy and neurotic, or even mutilating themselves by chewing their fur or skin - because they are kept in such an unnatural situation. This is like humans developing mental health problems when kept in solitary confinement. Boredom and isolation do not make for a happy animal. The author has seen numerous cases where behavioural problems have ceased after single rats were introduced to companions.
Two rats are often more affectionate than one, because they compete for your attention. A shy rat will usually learn to be friendly quickly if housed with a well-socialized companion; it learns from the other rat that humans are nothing to fear. The fastest way to socialize a shy rat is usually to house it with a friendly rat.
Two very nervous rats will still become affectionate towards you if they are given enough attention, but you may need to work harder to socialize them if both are shy. This may be the basis of the belief amongst some people that a single rat is friendlier than a pair of rats. If a pair of shy rats are handled often enough, they will soon become just as friendly as - but far happier than - any single rat. No matter how shy your rats are, frequent gentle handling and hand-feeding will win them over. Stick them up your sweater while you read or watch TV, and take them out of the cage to play on your lap for short periods, as often as you can.
Not usually. Rats are territorial animals, and they will defend their patch against others. When an adult rat meets a strange rat, she usually perceives it as a threatening, invading stranger. She may be frightened and/or aggressive towards the new rat. She may fluff up her fur, hiss, wag her tail, squeal, and attack the newcomer. However, after a week or two of careful management, most rats will accept a companion and will go on to become the best of friends.
The author has not yet had a rat that could not be introduced to a group, although it may happen! Adult female rats can be introduced to other females of any age. Adult males can usually be introduced easily to baby males - even retired stud rats, which have always lived alone or with females, can usually be introduced to baby males. Adult males can be introduced to other adult males, but this is more difficult.
The only situation where introduction may be too difficult is with animals which have always lived alone and are older - say, over a year old. Although many of these rats can accept a companion, and will have much happier lives afterwards, some may simply have become too antisocial and set in their ways. Some rats are vicious and have to live on their own, to stop them continually attacking other rats.
If you decide to try to introduce a companion to an older single rat, you could buy two younger rats. This means that one would not be left alone when the older rat dies, or if introduction proves too difficult. If the older rat does not accept the newcomers then the rats will have to live in two separate groups. Introducing two young rats to one senior rat often works well, as the youngsters play boisterously together, and do not pester the older rat.
Young rats up to around 12 weeks of age are easy to introduce - put them together on neutral territory first, but you can put them into a cage together the first day they meet. This cage should be cleaned out first if one of them has been living in it for a few days.
Introduce adult rats gradually, letting them meet on neutral territory first, and only putting them together in a cage once they are comfortable. This may occur on the first meeting, or it may take many meetings, several times a day, over a week or two. If any fights occur, break them up by spraying the rats with water from a water pistol or plant spray. They have to stop fighting to groom themselves. Put the rats away, and try again later.
If both rats are aggressive, the cage should always be freshly disinfected, so that it does not smell of just one of them; if a cage smells like her home, a rat will defend it against other rats. Ideally, you should move them into a cage which neither has lived in for a week or so before. Alternatively, if one rat is definitely the bully and the other a wimp (eg an adult and a baby), put them in the wimp's cage (without cleaning it out). She will feel more confident (like a football supporter at a home match!) and the bully will be less aggressive. When the rats first move into a cage together, it will usually take a week or two for them to become truly friendly. But after a couple of weeks, they will almost always become the best of friends.
It is important that you remain calm yourself. Rats are very good at detecting tension in humans, and if you are on edge, they will become nervous and defensive. This may seem strange, but we have seen numerous cases where all that was necessary for a successful introduction was a calm human! Remember that it may take a couple of weeks, and some effort, to introduce rats. The author has so far never failed to find suitable companions for a rat, although sometimes it has taken a few attempts to work out which animals just don't like each other.
Yes - both entire male and female rats will live happily in single-sex groups, and neutered males can live with either males or females. However, if you keep entire males with females, they will usually breed constantly.
Breeders often keep entire male rats in colonies of up to 6 boys, separating one male from the group for just a day or so when they want to breed from him. As long as the rat is not separated from his group for long, he can be reintroduced after mating. I have reintroduced males after they have lived with females for over a month, but this can be difficult.
Occasionally a male rat will become aggressive if his levels of male hormone are too high; he may start to bully his cage mates, and perhaps to fluff up his fur and hiss at people. This can occur at any time of life after about three months of age. If the aggressive rat is neutered, he will usually revert to his former friendly self after a few weeks, and will again live happily with his companions (even if you don't neuter him, an aggressive male rat should not be bred from; the tendency towards aggression is often inherited).
Neutered male rats can live with male or female rats. However, they often get along better with other male rats (regardless of whether or not the others are neutered, and regardless of how badly he got on with them beforehand).
Entire male rats can be introduced to other adult males, neutered males or baby males; in my experience it is very easy to introduce neutered males to entire males. Introducing entire adult males to other adults takes more time. Introducing adult males to babies is usually easy, but you do need to watch closely to ensure the baby is not battered by the adult.
Not really - any cage that's large enough for one rat (at least 12" x 24" floorspace) is large enough for two, and a once-weekly clean is usually sufficient to keep a pair of rats smelling sweet. Two rats are more interesting to watch than one - they tend to be more active, and you can watch them groom and play with each other. You don't need to feel so guilty if you have a busy day and cannot spend time with the rats. A single rat lives for his moments of freedom with you, but a pair can entertain themselves for the odd day. Of course, two rats will cost more to maintain, in terms of food and vets' fees, than one - but the extra cost is negligible compared to the quality it will add to the lives of the animals.
In conclusion, there is no good reason to keep a single rat, but there are many reasons to keep rats in company. Many concerned breeders and good pet shops feel so strongly about this that they refuse to sell their rats to people who intend to keep them singly. Rats which go to their new homes in pairs have a great start in life - a friend to play with, no difficult introductions, and the companionship of their owner.