Gerbils: Care and behaviour

Gerbils live for between three and four years. They're more suitable for children than guinea pigs, because they aren't as shy, and can tolerate more handling. Gerbils still need to be treated with respect, so they're better suited to older children who've learnt to handle small animals confidently and calmly. The type of gerbil most commonly kept as a pet is the Mongolian gerbil, which is, like most gerbils, a desert dweller in the wild, hiding from the sun in a burrow, and very clean compared to some rodents, such as mice.

Gerbil behaviour

Gerbils are social animals which recognise one another by scent, They get on well with other gerbils they've known since they were youngsters, but an adult gerbil is likely to attack a strange adult placed in its cage because it 'smells wrong'. A newly purchased gerbil is likely to smell particularly 'wrong', because it will have the smell of the pet store, and the food it was eating. Once gerbils are eating the same food, and using the same sort of bedding, their smell becomes more similar, and of course if you handle both gerbils, they will both smell of you. So you need to take time over introductions, and these should preferably be in a neutral area, after the gerbils seem quite calm in cages near one another.

Gerbils are much more enthusiastic chewers and diggers than hamsters or guinea pigs, so they need safe objects to chew and they like to be able to dig tunnels, so they need tough, escape-proof cages. They're also prey animals, which try to hide at any sign of danger, so they need hiding places, and though they're quite tolerant of handling, rough handling, or loud noises while they're being handled, can be very scary for them. However, if you're patient and gentle with your gerbils, they can learn to trust you, and relax enough in your hands for you to check their teeth, or to eat a titbit you offer them.

An attraction of gerbils is that they come out more in the daytime, though they're more active in the evening. They can be allowed out to explore, under supervision, and you do need to supervise, because they're such enthusiastic chewers and diggers. They're also fast movers, so only let them out when they are tame enough to be handled easily, otherwise they'll just try to escape from you when you want to put them back in their home. You really need a room without much clutter for a gerbil to explore, because they can get up to mischief very easily when you can't see them.

Housing

Gerbils need to be fairly warm, so they should be kept indoors rather than in a garage or outhouse. They need a nesting box, or some type of hidey hole to sleep in. Gerbils live in burrows in the wild, so you can recreate their natural habitat using any cylindrical object, such as toilet roll centres, and large pipes. Gerbils also like containers with sand to 'bathe' in. You can also give them other toys, like branches to climb up, and ladders to go to a platform. Avoid hamster wheels, which can damage their tails.

Some people use stacking systems to house their gerbils, though these may be unstable. Gerbils chew a lot, and can get through wood and plastic barriers, while cages with bars can damage their mouths. They can also swallow plastic, which can be fatal, because they can't digest it. A large aquarium is safe, though it should be big enough for your gerbil to have plenty of exercise. Do give your gerbil something to chew on that's safe, like a special chewing block you can get in a pet shop. You can use wood shavings (not cedar wood shavings) for bedding, and it will have to be partially changed every week, with soiled areas cleaned every day.

Gerbils like to live with other gerbils, though may fight strangers, so it's best to buy two young ones together than to introduce two adults to each other. Males are more likely to fight than females, when they become adult, but both sexes are less likely to do so the more room they have. If you want to introduce two adults to each other, say you want them to breed, it's still easier the younger they are. Wait a few days if you've just bought a new gerbil, so that the newcomer starts to smell more like your existing gerbil, from eating the same diet, and having the same bedding. Then try putting their cages near each other, and letting each explore the other's cage when its occupant is out. Make sure they have plenty of room to run away and hide if they want to, when they do finally meet. Young gerbils will playfight, and you'll be able to tell, with experience, the difference between playfighting and serious fighting, which looks fiercer and faster.

Feeding

Gerbils eat similar seed mixes to hamsters, and should also be given some fresh fruit or vegetables, such as carrot or apple. Don't forget to clear away rotting fresh food. They love sunflower seeds the way that some of us like chocolate, but don't indulge them too much or they won't be eating a balanced diet. They also like grubs and other forms of insect life, now and again, if you can bear to feed your pet these wriggly things. Gerbils may be desert animals, but they can't do without water, so their water bottle should always be full. Gerbils only need to be fed once a day. They can survive a weekend on their own, so long as the temperature doesn't drop, and they have clean bedding, a full water bottle, and some fresh fruit or veg that stores well, like carrot. If the central heating is going to be turned off when you're away, and the weather is cold, find someone with a warm house to care for your pet, and leave written instructions.

Health

Make sure you buy healthy looking, alert gerbils, rather than ones that just look cute! If a gerbil looks sad in the shop, it may be ill. There is a very nasty illness called Tyzzer's disease, which affects gerbils, which tend to look hunched up and miserable if they're infected. It's spread from one gerbil to another, so if you see a miserable-looking gerbil in a pet shop, it's not a good idea to handle it.

You can avoid health problems when you get your gerbils home by attending to their needs, especially their need to chew. They need chew blocks because they can get sores round their mouths if they chew cage bars, or teeth can grow too long if they can't chew at all. It's best to house them in an aquarium with chewing materials available, to avoid these problems. 

Gerbils may also have digestive problems if their food isn't fresh, or they haven't enough roughage, so make sure that old fruit and vegetables are cleared away, and don't feed them on crisps and other snacks meant for humans, however much they seem to like them! Colds and other snuffles can be avoided by making sure your gerbils are kept warm, their bedding is dry, and their cage is out of a draught.

Some gerbils are particularly prone to seizures, in fact so much so that gerbils are studied to learn more about epilepsy. This is partly genetic - there are seizure-prone lines of gerbils, so if you're buying a gerbil, it's worth finding out whether the gerbil's parents are prone to fits. That's not the whole story, though, because even if a gerbil is from a family that is prone to fits, you can prevent fits from being triggered, and even help young gerbils to be more resilient.

Fits tend to be stress-related, and you can reduce stress by careful handling, never blowing in your pet's face. One experiment showed how blasts of air could trigger fits in susceptible gerbils. Gerbils are also stressed by having their cages cleaned and all bedding removed, or worse still, being moved to a new cage. They need familiar smells to feel safe, so leave them some bedding when you clean, and take some of their bedding to a new cage.

Gerbils can handle stress better if they have another gerbil for company, and if they have enough to do in their cages, for example, being able to tunnel. You can help young gerbils handle stress better by separating them from their mothers only very briefly at first, A gerbil that has never been away from mother and siblings, and suddenly finds itself alone, is less able to cope than one that has gradually got used to being away from mum.

Having a companion and an interesting cage is important for gerbils' physical and mental health generally. The need to tunnel is especially important. If gerbils are stuck in a boring cage with no companions and nothing to do, they tend to go bonkers, just as you or I would! This is often shown in stereotypic behaviour, which is mindlessly repeated behaviour, like chewing cage bars obsessively. The solution is simple: make their cage as interesting as possible, and give them a compatible companion.

Handling

All new rodents need some peace and quiet when you first bring them home. They need a place to hide, and to build up confidence. So, though your little gerbil is a curious creature, let him get used to the sound of your voide, and your smell, and wait for him to come out of his hidey hole in his own time. Talk to him softly, and wait till he comes to you. You can try tempting him with some food. Because your gerbil is curious, he's quite likely to climb on your hand if you put it in his cage. Wait until he seems relaxed about being on your hand, then try lifting him an inch or so, then letting him down, before you pick up up properly. Hold him with both hands round him, when you do pick him up, and keep him near the ground so he doesn't hurt himself if he falls.

It's important to respect a gerbil's sleep - you'd be grumpy and startled if someone tried to lift you out of bed when you were fast asleep! And be very careful not to grab him by his tail, or his tail skin can come off. You can often catch a young gerbil by getting him to go up a tube, then closing the end with your hand.

Breeding

Gerbils will breed very easily, but remember that it isn't very easy to find good homes for youngsters when they're born, so find potential owners before you think of breeding. You can put friends on a waiting list for a baby gerbil, without making firm promises, because something could go wrong. They should be sensible friends of course, who you can trust to look after their baby gerbil properly. Only breed from healthy gerbils. Epilepsy is common in gerbils, and is inherited, so no gerbil with epilepsy should be bred from.

Just keep one male and one female together if you want them to breed, because of the risk of adults fighting. Gestation lasts from 23 to 28 days, and there are between three and seven pups in the litter. They're weaned at between three to four weeks, and you need to separate the sexes soon after this so they don't breed too young.

There are differences of opinion as to how old the breeding couple should be when you introduce them to each other. The younger they are, the lower the risk of fighting, but they aren't really mature enough to breed until they're 12 weeks' old. Litter mates will tend to get on well, but there's an increased risk of health problems from in-breeding, especially after a couple of generations, so it's safer to match gerbils from different litters. Carry out introductions gradually, leaving cages beside each other at first, or split a big tank with a wire or glass divider so the couple can get to know each other safely. Introduce the couple on neutral territory, watching out for fights.

Give the breeding couple more space than a single-sex couple. A 15-gallon aquarium is really the minimum size for a breeding couple, whereas a single-sex couple can live in a 10-gallon tank. The couple will get on better the more space they have, and they will soon have baby gerbils romping round their house, so need space for the new family. They'll also get on better if they have lots of toys, climbing equipment and hidey holes to take refuge in after marital tiffs.

The male helps to care for the litter, so you can keep the couple together after they have mated, in fact, if you do separate them, they may not get on well if you decide to put them back together again. Females carry on breeding until they're between 18 months and two years' old, and often mate soon after giving birth. This means a lot of baby gerbils if you keep a pair together all their lives - females can easily produce 50 pups or more in their lifetimes, though earlier and later litters tend to be smaller. Separating the couple is the only way to stop them breeding, but gerbils don't like to live alone, so keep a daughter from a litter as a companion for the mother, and a son to live with the father.

Gerbils are a lot happier about letting you handle their babies than are hamsters, but you should still leave the babies alone for the first week, and make sure you don't disturb the nest where the babies live when you clean the cage. You can start taming the babies from when they are ten days' old, going very gently and carefully. Handle them for very short periods at first, just picking them up and putting them down the first time. They move fast, and can jump out of your hands and hurt themselves if you aren't careful, so only lift them a short distance inside their home at first, until they have got used to you a bit.

The babies can go to new homes after they are about five weeks' old. Check that the new owners know enough about gerbils to be good owners, and ask if they plan to breed their gerbils. They may only want one gerbil from your litter if they plan to breed them, getting the mate from elsewhere to avoid inbreeding. If they don't plan on breeding gerbils, give the new owners two babies of the same sex, so your babies aren't lonely and can entertain their new owners by playing together.

Further reading:

Bertorelli, R., Adami, M., Ongini, E., (1995) The Mongolian gerbil in experimental epilepsy. Ital. J. Neurol. Sci. 16, 101–106

Buckmaster, Paul S. (2006) Inherited epilepsy in Mongolian gerbils, in Pitkänen A, Schwartzkroin PA, Moshé SL, eds. Models of Seizures and Epilepsy. San Diego: Elsevier; 2006.

Waiblinger, E. and Konig, B. (2004) Refinement of gerbil housing and husbandry in the laboratory. Alternatives to Laboratory Animals 32, 163–169.

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