Fighting Gerbils

This originally appeared in the September 1999 issue of The Nibbler, Journal of the National Gerbil Society.

Just recently I have had several enquiries from members and non-members wanting advice on what to do if there is an outbreak of violence amongst their gerbils.
Whilst gerbils can and do fight, fighting is quite a rare event and is usually caused as a result of dominance. The unfortunate thing is that when gerbils fight they do so very aggressively and will often kill the loser of a fight. This is almost certainly the reason why our little pets have a scientific name that is derived from a warrior called “Meriones” who is mentioned in Homer’s Iliad.

Gerbil Behaviour
Gerbils tend to live in family groups in the wild. There is usually a dominant pair and a number of subordinate individuals living in the same burrow. Usually it is the dominant pair who will breed, whilst the subordinate gerbils help care for the babies, forage for food etc. The dominant female produces hormones that tend to suppress the fertility of the other adult females in the burrow. What generally happens is that some of the subordinate gerbils will then leave the burrow and start their own colony elsewhere if there is any pressure within the group.
In captivity groups of gerbils do not have this ability to leave, and this is when there can be outbreaks of violence. It can be caused by too many males and females of breeding age confined in a tank or by a struggle for power, when perhaps the dominant gerbil is not as strong as it once was. Usually this occurs when the gerbil is two years of age or older, but it can occur earlier. Another time when there can be trouble is when a mother is living with daughters of about 6 months of age. This is probably because one of the daughters does not accept her subordinate position and tries to drive off her mother.
All gerbils play fight, this is characterised by boxing and jumping around. On the whole this allows gerbils to establish their hierarchy without serious conflict. This sort of activity is harmless. However, serious fighting will be obvious by bites around the head and tail area. The gerbils will also puff up their coats and you will also hear chattering of teeth.
The are often signs of impending trouble that can easily be overlooked in you are not aware of their significance. This is especially true in groups of females. A gerbil can be deprived of food or water as a prelude to fighting, a sudden loss of weight can be an indication of this. This is especially common where an older dominant female is having trouble with a younger subordinate. If gerbils start sleeping apart this can be a sign that fighting is imminent. Whilst boxing and chasing now and again is not especially significant. If there is a sudden increase in this activity this can be a bad sign.

Preventing Fighting
It then becomes necessary to separate the individual causing the problems. Most people make the mistake of removing the victim, in severe attacks this may well be necessary so that the gerbil can receive immediate veterinary treatment. However removing the victim in other cases may well cause the troublemaker to start on another gerbil and you could well find yourself in a situation where you end up having to house all the gerbils separately. It can be difficult to identify the perpetrator, as other gerbils will tend to gang-up on the loser in a fight. I have also known people say that they separated the two gerbils that had blood on them as they had obviously been fighting only to discover that they were both victims and that an uninjured gerbil was causing the trouble. Remember that the winner in a fight will nearly always be uninjured. Or will only have injuries round the head and mouth. Most of the injuries are caused to the loser once it is trying to run away. Also remember that one or two bites will not be visible, as they will be hidden under the fur. It is only where there have been a lot of injuries that they will be immediately obvious.

If you want to keep gerbils in groups, I find that it is better to keep males together. Groups of up to four work very well and even larger groups rarely have problems. If you keep more than two females together there is a slight risk that at some stage you may have to deal with fighting. This risk seems to increase the larger the number of females in the group. The amount of space available does seem to affect the likelihood of fighting. But some people have found that it isn’t overcrowding that causes fighting, but the opposite. Larger tanks or complex arrangements where tanks are linked together can make fighting more likely. This is probably a function of the way that gerbils mark their territory and larger areas mean it is easier for two competing gerbils to establish distinct territories of their own which encourages fighting between them. In the wild it is known that there is a lot of boxing and chasing at the pints where borders between territories overlap. But in the wild the loser can always run away.

First Aid
If you find that a gerbil has been fighting, how do you treat its injuries? (There are some pictures of typical injuries on this page). On the whole it is not necessary to do anything about bites and scratches. These rarely get infected or have any complication. They will heal in a few days. This is different to bites from other animals, such as cats etc, where often secondary infections set in. A gerbil that has been seriously injured will often have several problems that you will need to deal with:
Hypothermia – Injured gerbils are often cold and immobile. If possibly try and warm it up. You can use your hands to do this or you can place a hot water bottle or heated pad under the tank.
Dehydration – This can be a serious Injured gerbils will often not be eating and drinking and thy may have lost blood. Offer water with a dropper. You may have to get a vet to inject saline solution.
Anorexia – Injured gerbils will often have little appetite. You may have to try and offer a range of different foods as novel foods is often a good way of getting a reluctant gerbil to eat.
Remember that this first aid will probably not give immediate results. But by supporting your gerbil for a couple of days like this you give it the best chance of recovering. If the gerbil is not drinking, eating or remains cold make sure you consult a vet at the earliest opportunity.
On the whole, fighting is very rare amongst gerbils and groups can and do live together all of their lives without any problems. But to reduce the risk of difficulties I recommend the following:

  • Avoid keeping large groups of females together if possible.
  • Keep an eye out for trouble at all times.
  • Be especially careful if you have an older female with a group of daughters aged about 6 months.
  • Be aware that problems can arise later in life, especially once females get over the age of two.
  • Males can also fight, but in general males are less likely to fight than females are.