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One of the most important — and most-often-wrong — decisions in small-pet keeping is whether an animal should live with its own kind or completely alone. Pick your species for the honest answer, straight from our fact-checked care guides.
Needs company
African pygmy dormice are communal nesters (wild nests hold many adults) and should be kept in compatible groups, not singly.
Watch out: They’re also territorial — males can be aggressive in the breeding season, and lower density improves welfare, so give multiple separate nest boxes and avoid overcrowding.
It’s complicated
Campbell’s is naturally solitary; same-sex pairs are sometimes kept but frequently break down, and the PDSA advises against housing Russian dwarves together.
Watch out: One per cage is the safe default; any pair needs litter-mates raised together and a spare cage on standby.
Needs company
Chinchillas live in groups in the wild, so keep yours with at least one other compatible chinchilla (male/female pairs only if you plan to breed, or single-sex groups).
Watch out: Introduce new chinchillas gradually and near each other for a week first — they can be aggressive at first meeting.
Lives alone
Chinese hamsters are naturally territorial and, like the Syrian, should live on their own.
Watch out: They become aggressive toward cage-mates (especially in a small cage); never mix species or sexes.
It’s complicated
Siberian chipmunks may be kept in a compatible pair or group (a neutered male–female pair, one male with up to three females, or all-female groups) — but adult males usually fight, and any chipmunk may be aggressive to others.
Watch out: Give each animal its own nest box plus a spare. (Some other chipmunk species must always live alone.) In the EU/UK it’s illegal to buy, sell or breed them.
Colony animal
Degus are social colony animals and should never be kept alone — keep them with at least one other degu.
Watch out: They live in small groups in the wild and rely on that company for their wellbeing.
Lives alone
Unusually for a gerbil, duprasi are tolerant of solitude and often live perfectly happily alone; a carefully matched same-sex pair (raised together) can work.
Watch out: Pairs can fall out suddenly without warning, so for many keepers a single, well-handled duprasi is the safest choice — the opposite of the strictly-social Mongolian gerbil.
Social — best with company
Ferrets are highly social and usually enjoy living in groups (a “business”), though it depends on the individuals; a single ferret can be happy only with a lot of daily human interaction and play.
Watch out: Females must be spayed or hormonally managed regardless — a jill left in prolonged heat can develop fatal anaemia.
Social — best with company
Flying squirrels are social and do best with a companion, and they bond strongly to their keeper; a lone, ignored one does poorly.
Watch out: Daily interaction (hand-feeding in the early weeks) builds the bond, and rehoming is hard on them once bonded. Source captive-bred, never wild-caught.
Colony animal
Gerbils are clan animals and must never be kept alone; keep them in same-sex pairs or groups formed early in life and kept stable.
Watch out: Bonded clans can suddenly turn on each other (“declanning”), so check daily for fighting and be ready to separate — and never add an adult stranger to an established clan.
Needs company
Guinea pigs are herd animals; keep at least two. Good groupings are a neutered male with one or more females, two females, or brothers raised together.
Watch out: In some countries keeping a solitary guinea pig is illegal. Give each pig its own hides and resources so lower-ranking pigs aren’t bullied.
Lives alone
Syrian and Chinese hamsters must always live singly. Some dwarf species can sometimes live in same-sex pairs formed young — but they don’t need company to be happy.
Watch out: Even dwarf pairs often fall out later, and hamster fighting is serious (not play), so be ready to house them separately for good.
Lives alone
Hedgehogs are solitary and are kept one to a cage — they don’t need or generally want the company of other hedgehogs.
Watch out: Housing hedgehogs together risks stress and fighting.
It’s complicated
Mice are social and shouldn’t live alone — but females do well in groups while adult males are often aggressive and frequently can’t be housed together.
Watch out: The safest male groups are same-litter brothers grouped before weaning and never disturbed; never introduce unfamiliar adult males.
Colony animal
Prairie dogs are highly social colony animals; keeping a single one is not advised unless you can give it a very large amount of daily interaction. Neutered males can live together, as can females; a male–female pair needs the male neutered.
Watch out: Pregnant or nursing females can turn aggressive and may need separating. A lone prairie dog without huge daily attention becomes lonely, obese and nippy.
Needs a bonded partner
Rabbits are social and should live with at least one other friendly, compatible rabbit — a neutered male paired with a neutered female is the classic bond, because neutering reduces fighting.
Watch out: Bond them slowly on neutral territory; give room to be together and to get away from each other. A rabbit kept truly alone needs daily human company as a poor substitute.
Needs company
Rats are highly social and must never live alone; keep them in same-sex pairs or small groups (in mixed-sex groups, all males must be neutered).
Watch out: A solitary rat can become depressed even with lots of human attention — and rats housed together are just as friendly with people.
It’s complicated
Roborovskis don’t need company, but of the pet hamsters they’re the most likely to tolerate a same-sex pair or trio formed young from litter-mates.
Watch out: Pairs can still fall out later, so only try it with a spare cage ready to separate them for good.
Lives alone
Short-tailed opossums are strictly solitary and must live alone except for supervised, deliberate breeding.
Watch out: Housed together they’re aggressive and wound one another (even during the breeding “dance”), and adults are aggressive toward offspring. This is a hard rule.
Needs company
Spiny mice are highly social communal animals; keep them in small groups. Single-sex or neutered-male groups avoid runaway breeding.
Watch out: Isolated spiny mice become inactive and lethargic. Introduce newcomers carefully (they’re often attacked at first) and provide plenty of hides to reduce fighting.
Colony animal
Sugar gliders are colony animals and should never be kept singly; they do best in pairs or small groups (for example one male with several females).
Watch out: A glider kept alone needs an enormous amount of daily attention and can otherwise become stressed and self-mutilate.
Lives alone
A Syrian hamster is highly territorial and must always live singly, for its whole life.
Watch out: Two together (even same-sex) will fight, often fatally — there is no safe way to pair them.
It’s complicated
A single Winter White is happy. The RSPCA says dwarves like it can live together; the PDSA advises against housing Russian dwarves together because of dominance fights.
Watch out: The safe default is one per cage; if you pair from young litter-mates, use a large cage with duplicated resources and keep a spare cage ready.
The same answers as a quick reference (this is the crawlable version of the tool above):
| Species | Live alone? | The rule |
|---|---|---|
| African Pygmy Dormouse | Needs company | African pygmy dormice are communal nesters (wild nests hold many adults) and should be kept in compatible groups, not singly. |
| Campbell’s Hamster | It’s complicated | Campbell’s is naturally solitary; same-sex pairs are sometimes kept but frequently break down, and the PDSA advises against housing Russian dwarves together. |
| Chinchilla | Needs company | Chinchillas live in groups in the wild, so keep yours with at least one other compatible chinchilla (male/female pairs only if you plan to breed, or single-sex groups). |
| Chinese Hamster | Lives alone | Chinese hamsters are naturally territorial and, like the Syrian, should live on their own. |
| Chipmunk | It’s complicated | Siberian chipmunks may be kept in a compatible pair or group (a neutered male–female pair, one male with up to three females, or all-female groups) — but adult males usually fight, and any chipmunk may be aggressive to others. |
| Degu | Colony animal | Degus are social colony animals and should never be kept alone — keep them with at least one other degu. |
| Fat-Tailed Gerbil | Lives alone | Unusually for a gerbil, duprasi are tolerant of solitude and often live perfectly happily alone; a carefully matched same-sex pair (raised together) can work. |
| Ferret | Social — best with company | Ferrets are highly social and usually enjoy living in groups (a “business”), though it depends on the individuals; a single ferret can be happy only with a lot of daily human interaction and play. |
| Flying Squirrel | Social — best with company | Flying squirrels are social and do best with a companion, and they bond strongly to their keeper; a lone, ignored one does poorly. |
| Gerbil | Colony animal | Gerbils are clan animals and must never be kept alone; keep them in same-sex pairs or groups formed early in life and kept stable. |
| Guinea Pig | Needs company | Guinea pigs are herd animals; keep at least two. Good groupings are a neutered male with one or more females, two females, or brothers raised together. |
| Hamster | Lives alone | Syrian and Chinese hamsters must always live singly. Some dwarf species can sometimes live in same-sex pairs formed young — but they don’t need company to be happy. |
| Hedgehog | Lives alone | Hedgehogs are solitary and are kept one to a cage — they don’t need or generally want the company of other hedgehogs. |
| Mouse | It’s complicated | Mice are social and shouldn’t live alone — but females do well in groups while adult males are often aggressive and frequently can’t be housed together. |
| Prairie Dog | Colony animal | Prairie dogs are highly social colony animals; keeping a single one is not advised unless you can give it a very large amount of daily interaction. Neutered males can live together, as can females; a male–female pair needs the male neutered. |
| Rabbit | Needs a bonded partner | Rabbits are social and should live with at least one other friendly, compatible rabbit — a neutered male paired with a neutered female is the classic bond, because neutering reduces fighting. |
| Rat | Needs company | Rats are highly social and must never live alone; keep them in same-sex pairs or small groups (in mixed-sex groups, all males must be neutered). |
| Roborovski Hamster | It’s complicated | Roborovskis don’t need company, but of the pet hamsters they’re the most likely to tolerate a same-sex pair or trio formed young from litter-mates. |
| Short-Tailed Opossum | Lives alone | Short-tailed opossums are strictly solitary and must live alone except for supervised, deliberate breeding. |
| Spiny Mouse | Needs company | Spiny mice are highly social communal animals; keep them in small groups. Single-sex or neutered-male groups avoid runaway breeding. |
| Sugar Glider | Colony animal | Sugar gliders are colony animals and should never be kept singly; they do best in pairs or small groups (for example one male with several females). |
| Syrian Hamster | Lives alone | A Syrian hamster is highly territorial and must always live singly, for its whole life. |
| Winter White Hamster | It’s complicated | A single Winter White is happy. The RSPCA says dwarves like it can live together; the PDSA advises against housing Russian dwarves together because of dominance fights. |
Structured from Hayfold’s fact-checked care guides. When in doubt about bonding or introductions, go slowly and, for a serious falling-out, ask an exotic vet or a rescue.
Several small pets should never live alone: rats must be kept in same-sex pairs or small groups; guinea pigs are herd animals and must have at least one other guinea pig; gerbils are clan animals kept in same-sex pairs or groups formed early; rabbits need at least one other friendly, compatible rabbit (a neutered male with a neutered female is the classic bond); and sugar gliders and degus are colony animals that should never be kept singly. Chinchillas are also social and should live with at least one compatible chinchilla.
Most hamsters live alone. Syrian and Chinese hamsters are territorial and must always live singly for their whole life — two together will fight, often fatally. Some dwarf species (like Roborovskis) can sometimes tolerate a same-sex pair formed young from litter-mates, but they don’t need company to be happy, and pairs often fall out later, so only try it with a spare cage ready to separate them for good.
No — guinea pigs are herd animals and must not live alone; keep at least two. Good groupings are a neutered male with one or more females, two females, or brothers raised together. In some countries keeping a solitary guinea pig is illegal. Give each pig its own hides and resources so lower-ranking pigs aren’t bullied.
Yes — rabbits are social and should live with at least one other friendly, compatible rabbit. A neutered male paired with a neutered female is the classic bond, because neutering reduces fighting. Bond them slowly on neutral territory and give them room both to be together and to get away from each other; a rabbit kept truly alone needs daily human company as a poor substitute.
Some species do best solo: hedgehogs are solitary and kept one to a cage; Syrian and Chinese hamsters must live singly; and short-tailed opossums are strictly solitary and must live alone except for supervised breeding. Ferrets are highly social and usually enjoy company, but a single ferret can be happy with a lot of daily human interaction and play.
