Gnaw-proof tank 75L+ with deep substrate, for a pair
Social needs
Social; keep same-sex pairs or small groups
Diet
Quality gerbil seed/grain mix plus occasional protein
Time
Daily feeding and checks; weekly spot-cleaning
Cost
Low
Overview
The Mongolian gerbil is a small desert rodent that is active in short bursts through the day and night.
Hardy, clean and fairly low-odour, it is a good beginner pet for those who enjoy watching natural behaviour.
Gerbils are strongly driven to dig and tunnel, so their care centres on deep substrate for burrowing.
They are social and should not be kept entirely alone.
Housing
A gnaw-proof tank or convertible enclosure of at least 75 litres suits a pair, with a deep layer of substrate (20cm or more) so they can build real burrow systems.
Avoid plastic-only cages, which they quickly chew through.
Mix paper-based bedding with hay for stable tunnels, and add a sand bath, wooden chews and a solid-surface wheel of 20cm or more in diameter.
Keep them at room temperature, out of direct sun and away from damp.
Diet
Feed a quality gerbil mix of seeds and grains, scattered to encourage natural foraging.
Supplement occasionally with a little fresh vegetable, a mealworm or other small protein source, and offer hay for fibre and enrichment.
Fresh water must always be available from a bottle.
Limit fatty sunflower seeds and avoid sugary or citrus foods.
As desert animals gerbils drink little, but they still need constant access to clean water.
Health
Gerbils are generally robust but can suffer tail-skin injuries if handled by the tail tip, so always scoop them from the body.
Overgrown teeth, scent-gland tumours and stress-related seizures can occur.
Watch for sore noses caused by digging in dusty or dirty bedding.
Monitor weight and activity, and seek an exotics vet promptly for lethargy, lumps or breathing changes.
Temperament
Gerbils are curious and busy and rarely aggressive toward people.
They tame readily, often coming to the hand to investigate, and are engaging to watch as they dig, store food and groom each other.
They are social and should live in compatible same-sex pairs or small groups, ideally littermates introduced young.
Falling out (declanning) can occur, so monitor group harmony and do not house unfamiliar adults together carelessly.
A good fit for
Beginners wanting an active rodent
Keepers interested in digging behaviour
Those wanting a low-odour pet
Owners able to house a pair
Common mistakes to avoid
Shallow substrate preventing natural burrowing
Plastic cages they chew through
Handling by the tail, causing injury
Keeping a single, lonely gerbil
Is your enclosure big enough?
Minimum volume75 litres (20 US gallons)
CompanyCannot be kept alone. The minimum is 2, and the space above is for that group.
Small mammals are prey animals. They mask pain and illness by instinct, so by the time something is obvious it is usually already advanced.
Go now
Not eating, or eating far less than normalCall an exotics vet. Bring a recent weight if you have one. In a hindgut fermenter the gut slows and then stops when food stops moving through it. This is the single most common emergency in small mammals.
8 hours
No droppings, or droppings suddenly tiny, misshapen or scarceCall an exotics vet now. Take a photo of the litter tray. Output is the most reliable read on gut movement there is, and it fails before the animal looks unwell.
8-12 hours
Sitting hunched, pressed to the floor, unwilling to moveGo now. A hunched, still posture in a prey animal is a pain posture.
Now
Audible teeth grinding or crunchingGo now. Soft tooth purring is contentment. Loud, slow grinding is pain.
Now
Hard, bloated or drum-tight abdomenGo now. Do not offer food or attempt to massage the abdomen. Gas or an obstruction can become fatal within hours and needs imaging, not home care.
Now
Laboured breathing, open-mouth breathing, or clickingGo now. Keep the animal cool and undisturbed in transit. Most small mammals are obligate nose breathers; open-mouth breathing means they are already struggling.
Now
Maggots or fly eggs anywhere on the animal, especially the rearGo now. Do not attempt to wash them off first. Flystrike can kill within a day. Risk rises sharply in warm weather and in any animal with a dirty or damp rear.
Now
Today
Head tilted persistently to one side, or circlingBook today. Several causes, most of which respond far better to early treatment.
Today
Weight down 5 percent or more since the last weighingCall today, and bring the weight history. Weight falls before appetite visibly changes. This is why weekly weighing is worth the two minutes.
Today
Soon
Drooling, wet chin, or dropping food while trying to eatBook a dental check. Continuously-growing teeth can overgrow into the tongue or cheek long before the animal stops trying to eat.
A few days
Scratching hard enough to break skin, or bald patches spreadingBook an appointment. Mites and fungal infections spread, and some transfer to other animals in the household.
A few days
Have the number of an exotics-competent practice saved before you need it. Most general small-animal clinics do not treat rabbits or rodents out of hours, and finding one at 11pm is not realistic.
This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it — and the time to find one is before you need one.
Can a mongolian gerbil eat that?
Most small companion mammals are hindgut fermenters: the gut is a fermentation vessel that has to keep moving, and sudden rich food stops it.
Never (19)
AlcoholNo safe amount at any body weight on this site.
never
AvocadoPersin, concentrated in the skin, stone and leaves. Implicated in cardiac damage across birds, rodents and reptiles.
never
Bread and baked goodsRefined starch ferments in the hindgut and causes gas and stasis. No nutritional case for it either.
never
CaffeineCoffee, tea and energy drinks. Cardiac and neurological toxicity at tiny doses for an animal this size.
never
ChocolateTheobromine and caffeine. Small mammals and reptiles cannot clear either.
never
DairyAdults are lactose intolerant and the gut flora cannot handle it.
never
Dried fruitSugar concentrated several times over, and it sticks to the teeth. Most commercial small-pet treats are exactly this.
never
GarlicSame allium toxicity as onion, and more concentrated by weight.
never
Iceberg lettuceAlmost entirely water with negligible nutrition, and it contains lactucarium, which causes diarrhoea in quantity. It displaces food that would have been useful.
never
LeekAllium family. Same mechanism as onion and garlic.
never
MeatA hindgut fermenter has no way to process animal protein. It disrupts the gut flora the animal depends on.
never
MushroomsNot part of any of these animals' natural diet, and the risk from misidentified varieties is not worth the zero upside.
never
NutsFat and phosphorus loads a herbivore is not built for, and a choking risk.
never
OnionOrganosulphur compounds damage red blood cells. The whole allium family is out.
never
PotatoSolanine in the skin and any green part, plus a starch load the hindgut cannot handle.
never
Raw beansLectins. Also a gas producer in a species that cannot vomit or belch.
never
RhubarbVery high in soluble oxalate, high enough to cause acute kidney injury. The leaves are worse than the stalks.
never
Salty or seasoned human foodSalt, oil and seasoning. Crisps, chips, seasoned leftovers and processed meat are all out.
never
SweetcornThe hulls are indigestible and are a recognised blockage risk in small herbivores.
never
Rare treats (13)
AppleSugar. The seeds contain a cyanogenic compound and must be removed. A thin slice, once or twice a week. Never the seeds or core.
rare treat
BananaVery high in sugar and starch, and most animals will overeat it given the chance. A slice the width of a fingernail, rarely.
rare treat
BlueberrySugar, but a small portion size makes it easy to control. One or two berries, twice a week.
rare treat
Brussels sproutsHighly gas-forming. Half a sprout, rarely.
rare treat
CarrotSold as the archetypal rabbit food and it is nothing of the kind: carrot is a root vegetable with a high sugar content. The leafy tops, by contrast, are an excellent green. A thin slice as a treat. The tops can be fed freely.
rare treat
CauliflowerOne of the most gas-forming brassicas. A very small piece, occasionally.
rare treat
GrapesVery high in sugar. Halve them, because a whole grape is a choking hazard. One halved grape, rarely.
rare treat
OrangeAcidic and sugary; can irritate the mouth and gut. A tiny segment, rarely if at all.
rare treat
PearSugar. Remove the seeds. A thin slice occasionally.
rare treat
PeasHigh in starch and sugar. The pods and leaves are better than the peas. A few pods occasionally.
rare treat
StrawberrySugar, though lower than most fruit. The leaves are actually the better part. Half a small berry, once or twice a week.
rare treat
TomatoThe ripe flesh is safe in small amounts. The leaves, stems and any green fruit contain solanine and must never be offered. A small piece of ripe flesh, occasionally. Never the plant.
rare treat
WatermelonSugar and a very high water content, which together can loosen the gut. Remove the seeds. A small cube in hot weather, rarely.
rare treat
Occasional (17)
BasilSafe and well liked. Rotate rather than relying on it. A few leaves.
occasional
Bok choyGood green, mildly goitrogenic like other brassicas. A leaf or two a few times a week.
occasional
BroccoliNutritious but a notable gas producer. Leaves and stalk are better tolerated than the florets. A small floret or a piece of stalk, twice a week.
occasional
CabbageA brassica. Gas-forming in quantity, and goitrogenic with heavy long-term feeding. A small piece, once or twice a week.
occasional
CelerySafe and well liked. Cut across the stalk so the long fibres cannot catch. A short piece, cut into segments.
occasional
ChardSame oxalate issue as spinach. A small leaf, occasionally.
occasional
CourgetteSafe and mild. Serve raw. A few slices a few times a week.
occasional
CucumberSafe, but it is mostly water with very little in it. Useful for hydration in warm weather, poor as a staple. A few slices.
occasional
DillSafe in rotation. A few fronds.
occasional
Green beansSafe cooked or raw in small amounts. Gas-forming in quantity. One or two, occasionally.
occasional
KaleHigh in calcium and a mild goitrogen. Genuinely nutritious, but not the everyday green it is often sold as. A leaf or two, two or three times a week.
occasional
MintSafe in small amounts; strongly flavoured and not every animal wants it. A leaf or two.
occasional
ParsleyNutritious but relatively high in calcium. Fine in rotation, not as the whole green portion. A few sprigs, a few times a week.
occasional
PumpkinSafe and well tolerated in small amounts. A small cube occasionally.
occasional
RocketPeppery and well tolerated in rotation. A small handful, a few times a week.
occasional
SpinachHigh in oxalates, which bind calcium and contribute to bladder sludge and stones in animals prone to them. A single small leaf, no more than once or twice a week.
occasional
WatercressNutritious, strongly flavoured, high in calcium. A small handful occasionally.
occasional
Everyday foods (6)
Bell pepperOne of the best everyday vegetables here: high in vitamin C, low in sugar, no oxalate problem. Remove the seeds and stalk. A few strips daily.
everyday food
Carrot topsThe leaves are a proper green and much better food than the root. A handful as part of the daily greens.
everyday food
CorianderWell tolerated, aromatic, and most animals take it readily. Part of a daily mixed handful.
everyday food
Dandelion leavesOne of the best greens available, and free. Pick well away from roadsides and anywhere that may have been sprayed. A generous handful daily.
everyday food
Grass hayShould be about 80 percent of what this animal eats, available at all times. It is what wears the teeth down and what keeps the gut moving. Unlimited, always.
everyday food
Romaine lettuceDark leafy lettuce with real nutritional content and a good water balance. A generous handful daily as part of a mixed selection.
everyday food
That food is not on our list. Do not offer it on a guess — check with an exotics vet, or leave it out. Nothing in a small mammal's diet is urgent enough to risk it.
Introduce any new food one at a time, in a small amount, and wait two days before adding another. A change in droppings is the earliest signal that something did not suit.
Setup, monthly, first year and across a whole life, itemised and with the electricity worked out from the actual wattage. Published figures for the same animal disagree by a factor of four, so the calculator shows ranges rather than picking one.
Beginner
Beginner
Beginner
Intermediate
Intermediate
Intermediate