African Pygmy Dormouse
No authority gives a minimum size — the evidence is that they need a TALL, arboreal, genuinely gap-free enclosure with climbing and elevated nest boxes. Aim as large and tall as you can.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
The space must also provide:
- A tall enclosure with a climbing grid/branches and multiple elevated nest boxes
- Genuinely gap-free (fine mesh or glass) — they’re tiny escape-artists
- Kept warm (about 20–23°C; cold triggers torpor)
Source: Lang et al. 2020, J. Vet. Behavior — dormouse enrichment/welfare · full african pygmy dormouse care guide →
Campbell’s Hamster
Far bigger than shop cages, with deep bedding to burrow. A tank or narrow-barred cage suits a small dwarf; include a sand area and, if pairing is attempted, duplicated resources.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
🕳️ Minimum bedding depth to dig/burrow: 15 cm.
The space must also provide:
- A large secure enclosure with a solid floor (narrow bars or a ventilated-lid tank)
- Deep bedding to tunnel, a sand area, and a dark nest box
- A large, solid, axle-free wheel and things to gnaw
Source: RSPCA — Creating a good home for hamsters · full campbell’s hamster care guide →
Chinchilla
Authorities specify a large, tall, multi-level cage (with no uninterrupted drop over ~60 cm) rather than a single footprint number — chinchillas are agile climbers and jumpers.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
The space must also provide:
- A tall, multi-level cage with shelves to jump and rest on
- Solid resting areas over any wire floor (bare wire damages their feet)
- Kept cool (ideally 10–18°C) with a daily dust bath
Source: RSPCA — Creating a good home for chinchillas · full chinchilla care guide →
Chinese Hamster
Far bigger than shop cages, with deep bedding to burrow. A slim, agile climber, so use a ventilated-lid tank or narrow bars, with height to climb as well as floor to dig.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
🕳️ Minimum bedding depth to dig/burrow: 15 cm.
The space must also provide:
- A large secure enclosure with a solid floor (narrow bars or a ventilated-lid tank)
- Deep bedding to tunnel plus climbing enrichment, and a dark nest box
- A large, solid, axle-free wheel and things to gnaw
Source: RSPCA — Creating a good home for hamsters · full chinese hamster care guide →
Chipmunk
The RSPCA specifies a large, secure enclosure “ideally the size of a large aviary” (tall enough to walk into) rather than a footprint number — with a solid floor and substrate deep enough to dig.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
The space must also provide:
- An aviary-scale enclosure with lots of vertical climbing space
- A solid floor (never wire mesh) with deep substrate to dig
- Branches/ropes of untreated wood, nest boxes and hiding places
Source: RSPCA — Chipmunks · full chipmunk care guide →
Degu
Authorities specify a large, tall, multi-level metal cage (the bigger the better) rather than a single number — degus chew through plastic and wood, and love to climb.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
The space must also provide:
- A tall, multi-level metal cage with narrow bar gaps
- A solid base with deep bedding to dig, plus hay-filled nest boxes
- Kept below ~20°C, with a dust bath a few times a week
Source: RSPCA — Creating a good home for degus · full degu care guide →
Fat-Tailed Gerbil
A secure glass tank or large barred cage with a solid floor and a deep layer of sand (or sand/soil) at least 15–20 cm deep to dig — kept dry, warm and well ventilated.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
🕳️ Minimum bedding depth to dig/burrow: 15 cm.
The space must also provide:
- 15–20 cm of dry sand (or sand/soil) to dig and burrow
- A separate sand bath, hides, tunnels and a solid wheel
- Kept warm and dry (about 20–25°C) — damp causes illness
Source: Royal Veterinary Center (exotics clinic) — Duprasi care sheet · full fat-tailed gerbil care guide →
Ferret
A multi-level wire cage of at least about 90 × 90 × 60 cm (3 × 3 × 2 ft) — bigger is better. The cage is only for downtime: ferrets also need 2–4 hours of supervised play outside it every day.
Cited minimum (for downtime housing (plus 2–4 h/day out)): 90 × 90 × 60 cm · floor area 0.81 m² (8,100 cm²)
The space must also provide:
- A solid or padded floor (bare wire hurts their paw pads)
- Hammocks or fabric huts to sleep in, and a litter tray (never clumping cat litter)
- 2–4 hours a day of supervised, ferret-proofed play outside the cage
Source: Merck Veterinary Manual — Providing a Home for a Ferret · full ferret care guide →
Flying Squirrel
Authorities don’t publish exact dimensions for pet flying squirrels — the guidance is a TALL, escape-proof cage with branches to climb and glide and a high nest box. Aim as tall and secure as possible.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
The space must also provide:
- A tall cage with branches to climb and glide, and a nest box placed high
- Escape-proof, with clean dry bedding
- Kept warm indoors (cold triggers torpor)
Source: WebMD (veterinarian-reviewed) — Can I have a pet flying squirrel? · full flying squirrel care guide →
Gerbil
A deep tank-style “gerbilarium” around 50 cm high with 20–30 cm of substrate — solid glass or plastic sides, a secure mesh top, and a solid floor. Barred cages aren’t recommended (gerbils injure their legs on the bars and gnaw them).
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
🕳️ Minimum bedding depth to dig/burrow: 20 cm (20–30 cm ideal).
The space must also provide:
- 20–30 cm of a woodchip-and-hay substrate so they can dig stable burrows
- Solid sides (not bars) and a secure mesh top
- A stone or rough surface to wear down their claws
Source: RSPCA — Creating a good home for gerbils · full gerbil care guide →
Guinea Pig
Authorities stress “as much floor space as you can give” on a solid floor rather than a single number — guinea pigs run rather than climb, so floor area matters far more than height.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
The space must also provide:
- A solid floor (never grid/wire — it hurts their feet) with deep litter
- A large exercise area plus secure hides (as many hiding places as pigs, plus one)
- Kept at 17–20°C, out of direct sun and heat
Source: RSPCA — Creating a good home for guinea pigs · full guinea pig care guide →
Hamster
Authorities emphasise “far bigger than the cages sold for them,” with deep bedding to burrow, rather than one fixed number — so treat any pet-shop “minimum” as a floor to exceed.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
🕳️ Minimum bedding depth to dig/burrow: 15 cm.
The space must also provide:
- A large secure enclosure with a solid floor (never wire mesh)
- Deep bedding to dig and tunnel, plus a dark nest box
- A large, solid, axle-free wheel and things to gnaw
Source: RSPCA — Creating a good home for hamsters · full hamster care guide →
Hedgehog
A single hedgehog needs a secure, well-ventilated cage with a minimum floor of about 0.6 × 0.9 m (2 × 3 ft) — and bigger is better.
Cited minimum (for one hedgehog (they live alone)): 90 × 60 cm · floor area 0.54 m² (5,400 cm²)
🕳️ Minimum bedding depth to dig/burrow: 8 cm.
The space must also provide:
- A secure lid (they climb and escape) and good ventilation — no glass aquariums
- A hide, a solid-surface exercise wheel, and 8–10 cm of bedding to burrow in some areas
- A thermostatically-controlled 24–29°C — the make-or-break factor for a hedgehog
Source: Merck Veterinary Manual — Management of Hedgehogs · full hedgehog care guide →
Mouse
Authorities give no single minimum — the guidance is a large, secure, escape-proof enclosure with plenty of floor space and, crucially, deep bedding to dig. More space is always better.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
🕳️ Minimum bedding depth to dig/burrow: 2 cm.
The space must also provide:
- A big tank or a cage with very narrow bar spacing (mice squeeze through tiny gaps)
- At least ~2 cm of bedding (ideally deeper) to dig, plus nest sites
- Kept out of direct sun and heat
Source: RSPCA — Creating a good home for mice · full mouse care guide →
Prairie Dog
Authorities say “the biggest you can afford” rather than one number — a very large, chew-proof (stainless steel or plexiglass), escape-proof enclosure with deep bedding to burrow.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
🕳️ Minimum bedding depth to dig/burrow: 15 cm.
The space must also provide:
- Chew-proof material (stainless steel or plexiglass — never wood) that’s escape-proof and lockable
- 6–12 inches (15–30 cm) of bedding to burrow, and high sides
- At least one open/ventilated side; kept around 21°C
Source: VCA Hospitals — Prairie Dogs: Housing · full prairie dog care guide →
Rabbit
For two medium rabbits, a living space no smaller than 3m × 2m × 1m high (about 10 × 6 × 3 ft), combining shelter with an attached exercise area they can use whenever they like.
Cited minimum (for a pair of medium rabbits): 300 × 200 × 100 cm · floor area 6 m² (60,000 cm²)
The space must also provide:
- Room to take several hops, stand fully upright without ears touching the roof, and stretch out flat
- A solid (non-wire) floor and a raised, predator-proof shelter
- Draught-free, dry, well-ventilated housing with hiding places
Source: RSPCA — Creating a good home for rabbits · full rabbit care guide →
Rat
Authorities give no single minimum — the guidance is “as large as possible,” a large, tall, multi-level cage. More space is always better.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
The space must also provide:
- A large, tall, multi-level wire cage with solid floors (never wire mesh)
- Bar spacing narrow enough that a rat can’t push its head through
- Room to climb, plus daily supervised time out of the cage
Source: RSPCA — Creating a good home for rats · full rat care guide →
Roborovski Hamster
Far bigger than shop cages, with deep bedding to burrow. Because a Robo is tiny, use a glass/plastic tank with a ventilated lid (it squeezes through wide bars) and a generous sand area to dig and bathe.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
🕳️ Minimum bedding depth to dig/burrow: 15 cm.
The space must also provide:
- A tank-style enclosure with a solid floor and escape-proof ventilated lid
- Deep bedding to tunnel plus a deep sand area for digging/bathing
- A large, solid, axle-free wheel and things to gnaw
Source: RSPCA — Creating a good home for hamsters · full roborovski hamster care guide →
Short-Tailed Opossum
Published husbandry keeps single adults in rat- or guinea-pig-sized caging (breeding needs more, at least ~2,000 cm²) — provide a secure, escape-proof enclosure with climbing and a nest box, housed strictly alone.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
The space must also provide:
- A secure glass tank with a locking, fine-mesh lid
- Climbing branches (semi-prehensile tail) and a hide/nest box
- Kept warm (about 23.5–26.5°C); housed strictly alone
Source: ILAR Journal — laboratory husbandry of Monodelphis · full short-tailed opossum care guide →
Spiny Mouse
Published husbandry uses large, escape-proof, well-ventilated caging with climbing — there’s no pet-specific minimum, so give as much space as you can. Escape-proof lids are essential (they leap out).
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
The space must also provide:
- A big glass tank or barred cage with a secure fine-mesh lid
- Climbing structures and multiple hiding tubes/shelters
- Kept warm (about 21–26°C)
Source: Haughton, Gawriluk & Seifert 2016, JAALAS — spiny mouse husbandry · full spiny mouse care guide →
Sugar Glider
A large, secure, TALL cage of at least about 61 × 91 × 91 cm (24 × 36 × 36 in) — and bigger is better. Height matters because gliders climb and glide.
Cited minimum (for a pair/colony (never one)): 91 × 61 × 91 cm · floor area 0.56 m² (5,551 cm²)
The space must also provide:
- Bar spacing no wider than about 2.5 × 1.3 cm
- A high nest box/pouch with headroom so elbows don’t rub the roof (which tears the gliding membrane)
- Safe climbing branches and a solid, smooth-interior wheel — and a companion (never keep just one)
Source: Merck Veterinary Manual — Providing a Home for a Sugar Glider · full sugar glider care guide →
Syrian Hamster
Far bigger than the cages sold for a Syrian, with deep bedding to burrow — treat any pet-shop “minimum” as a floor to exceed. As the largest hamster it needs the most floor space and a large wheel.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
🕳️ Minimum bedding depth to dig/burrow: 15 cm.
The space must also provide:
- A large secure enclosure with a solid floor (never wire mesh)
- Deep bedding to dig and tunnel, plus a dark nest box
- A large, solid, axle-free wheel (big enough for a Syrian’s back) and things to gnaw
Source: RSPCA — Creating a good home for hamsters · full syrian hamster care guide →
Winter White Hamster
Far bigger than shop cages, with deep bedding to burrow — a floor to exceed, not a target. A tank or narrow-barred cage suits a small dwarf; include a sand area.
No authority publishes a single minimum size for this species — the guidance is “as large as possible.” Focus on meeting the requirements below and giving as much room as you can.
🕳️ Minimum bedding depth to dig/burrow: 15 cm.
The space must also provide:
- A large secure enclosure with a solid floor (narrow bars or a ventilated-lid tank)
- Deep bedding to tunnel, a sand area, and a dark nest box
- A large, solid, axle-free wheel and things to gnaw
Source: RSPCA — Creating a good home for hamsters · full winter white hamster care guide →
The same minimums as a quick reference (this is the crawlable version of the tool above):
