Quick answer: Where space is tight, look first at springtails, isopods, smaller millipedes and cockroaches, all of which we sell. Springtails can share another pet's enclosure; a starter group of isopods settles in a 3-litre tub, though our standard is 11 litres; a small group of Thai Rainbow millipedes is comfortable on about 30 by 30 cm; and a 9 to 15 litre box suits a starter cockroach colony.
If you want an interesting pet that fits a flat, won't disturb the neighbours, and doesn't cost a fortune to run, you've got more options than you might think. The best small pets stay compact, are simple to look after, and suit a shelf, desk or modest cage rather than a whole room. This guide runs through some of the best - starting with the invertebrates, which cost little and take up very little room, then the popular small mammals, reptiles and other inverts - so you can find one that matches your space, time and budget.
A quick word on what makes a small pet flat-friendly: a small enclosure footprint, little or no noise, minimal smell when kept clean, modest handling needs, and low running costs. Always check your tenancy agreement and local rules, and make sure you can reach an exotics-friendly vet for the species that need one, before bringing anything home.
How Much Space Does Each Need?
Here is how much room the springtails, isopods, millipedes and cockroaches below each take, from our own care guides:
| Pet | Enclosure | Room it takes | Good to know |
|---|---|---|---|
| Springtails | Seeded into another pet's damp substrate, or a lidded culture tub | None inside an isopod tub or vivarium; a small tub or jar on their own | A 250ml culture seeds one small to medium enclosure |
| Isopods | A vented tub with a damp end, and flake soil, white-rotted hardwood and organic topsoil under leaf litter | 3 litres settles a starter group, or 4 to 10 for more room; our standard is 11 litres, and 17 or more for the bigger species | Bigger tubs are easier: they hold humidity and temperature gradients more reliably |
| Smaller millipedes (Bumblebee, Ivory, Thai Rainbow) | A tub with a tight, vented lid and a bed at least as deep as the animal is long: 10 cm at least for Ivories and Thai Rainbows, 5 to 8 cm for Bumblebees | About 30 by 30 cm of floor for a small group of Thai Rainbows | Bed depth matters more than floor area; climbers such as the Thai Rainbow use some height too |
| African giant millipedes | A tank with a fastening lid, at least as wide as the longest millipede and twice as long, and a bed at least as deep as an adult is long (an African Giant Black can reach around 33 cm) | At least 66 by 33 cm of floor for one or two of the largest African Giant Blacks, at around 33 cm, or 60 by 30 cm for one or two adult Chocolates, in a tank tall enough to hold the bed | Floor space and depth matter more than climbing height for the burrowing African Giant Black; give the climbing Chocolate some height |
| Cockroaches | A clip-lock tub with cross-ventilation and a secure lid, and cork bark or egg crate filling the airspace | A 9 to 15 litre box suits a starter colony | Surface area matters more than floor space, because they pack into tight crevices |
Isopods: Tiny Living Clean-Up Crews
Isopods - woodlice, roly-polies, pill bugs - have quietly become one of the most popular micro-pets in the UK, and for good reason: they cost little to keep, need little upkeep and take up very little room. Hardy, colourful options like Armadillidium morphs or "Dairy Cow" isopods live happily in a ventilated tub or nano-tank on a bookshelf, with moist substrate, leaf litter, moss and cork bark. They're silent, low in odour when kept clean, breed readily, need only a little fresh food twice a week, and largely look after themselves - a well-kept colony effectively lasts as long as you keep it going. If you want a fascinating low-effort pet in minimal space, they're hard to beat - see our beginner's guide to keeping isopods to get started, and browse the isopods for sale.
Millipedes: Gentle Giants for Small Spaces
Millipedes are charming, slow-moving and ultra-low-maintenance. The African Giant Black millipede can reach around 33 cm, though most adults stay smaller. It is calm and easy to keep, while smaller species fit a compact setup. One or two adult giants need at least 66 by 33 cm of floor for the largest African Giant Blacks, or 60 by 30 cm for Chocolates, and the smaller species far less; either way, deep, damp substrate of organic soil and white-rotted wood, leaf litter and bark is all they need - and it's worth avoiding coco coir as the base, since millipedes eat their substrate and coir offers them little nutrition. Diet is mostly decaying wood and leaf litter, with a little fresh vegetable two or three times a week and a calcium source, and running costs after setup are low. Browse the millipedes for sale.
Hermit Crabs: Social Shell-Swappers
Land hermit crabs are quirky, sociable crustaceans that swap shells as they grow - endlessly entertaining to watch. They're best kept in small groups in a warm, humid "crabitat" (around 40-75 litres) with moist substrate, both fresh and salt water dishes, climbing décor and a selection of spare shells. They're active at night and, with good care, can live a decade or more.
Springtails: The Ultimate Micro-Pet
Even smaller than isopods, springtails are tiny invertebrates that do not bite or sting people or pets, thrive in a small moist tub and double as a clean-up crew in bioactive setups. They need very little upkeep, take up next to no space, and are a great first culture for anyone curious about microfauna.
Cockroaches: The Display Kind, Not the Kitchen Kind
Pet cockroaches have nothing in common with the pest species beyond the name. Madagascar hissing cockroaches are the classic choice: big, slow and calm enough to sit on a hand. The flower, jade and glowspot species are smaller, brightly patterned display animals, better watched than handled. A ventilated tub with a secure lid (several species climb smooth plastic and a few can fly), a few centimetres of substrate, cork bark or egg crate to hide under, and a heat mat on the side of the tub, on a thermostat, to hold the mid to high twenties, is the whole setup. They eat fruit, vegetables and a little dry protein a couple of times a week, and a tub that is kept clean has next to no smell.
If invertebrates are new to you, start with a beginner's guide to bug pets, which covers choosing a first species and the safety and legal points worth knowing before you buy.
Rats: Clever, Social Companions
Fancy rats are among the most intelligent and affectionate small pets, learning their names and simple tricks and bonding with their owners. They need a roomy multi-level cage with hammocks and toys, daily handling and out-of-cage time, and company - they should never be kept alone. Quiet and mostly active in the evening, they suit people who want a hands-on pet and are home regularly.
Hamsters: Classic First Pets
Hamsters are popular first pets - solitary, mostly nocturnal, and better for watching than constant handling. A single dwarf or Syrian hamster needs a surprisingly large cage by old standards (bigger is always better) with deep bedding for burrowing and a solid-surface wheel. Gentle evening handling works best, as they can nip if startled awake.
Mice: Tiny and Entertaining
Fancy mice are inquisitive and fun to watch, though quick and a little small for young children to handle much. They want a secure cage or tank with hideouts, chews and climbing structures, and frequent cleaning, as they can get smelly if bedding is neglected. Cheap to buy but they appreciate plenty of enrichment.
Guinea Pigs: Chatty and Gentle
Guinea pigs are sociable, vocal and gentle, making soft squeaks and purrs rather than anything that would bother neighbours. They need a fair bit of floor space - a generous run for a bonded pair, as they should never live alone - plus daily fresh hay, vitamin-C-rich veg and pellets. Friendly and good with supervised older children, with slightly higher running costs than smaller rodents.
Rabbits: Larger but Flat-Friendly
Rabbits sit at the bigger end of "small pets," but many adapt well to indoor life and can be litter-trained. They need a large pen plus daily free-roam time in a bunny-proofed space, daily hay and greens, and budget for neutering, vaccinations and dental checks. They bond closely with owners, often following people about like small dogs.
Leopard Geckos: Friendly, Low-Drama Lizards
Leopard geckos are among the easiest reptiles for a smaller home - docile, silent, and tolerant of gentle handling. They need a secure vivarium (around 60cm-plus) with a warm and a cool end and hides on both sides, and an insect diet (crickets, roaches, mealworms) dusted with calcium. Active in the evenings, they suit owners out during the day. Startup costs are moderate, running costs low.
Bearded Dragons: Interactive "Mini Dinosaurs"
Bearded dragons are calm, characterful reptiles that often enjoy sitting with their owners - but they need more space and kit than a gecko: a large vivarium (120cm or so), strong basking heat and UVB lighting, and a daily mix of live insects and vegetables. Wash hands after handling (salmonella risk), and budget for the higher electricity and equipment costs.
Ball Pythons: Calm, Compact Snakes
Ball pythons are shy, gentle snakes that suit calm households. They need a secure vivarium with controlled heat and humidity and hides on both warm and cool ends, and are fed defrosted rodents every week or two. Day-to-day care is minimal, but they're a serious long-term commitment - they can live 20-30 years.
Hedgehogs: Quiet, Spiky Night Explorers
African pygmy hedgehogs are unusual, appealing pets for more experienced keepers. They need a decent floor space with a solid wheel and deep bedding, consistent warmth, and an insect-based diet. They're solitary and nocturnal, and need patient handling from young to tame down - check current UK regulations and that you have an exotics vet before committing.
Frogs: Colourful Display Pets
Frogs are excellent "look, don't handle" pets. Tree frogs, aquatic frogs and ground-dwelling species each offer something different, in a glass enclosure (around 40-75 litres) sized to their needs, with dechlorinated water and a diet of live insects. Note that some males call at night, so check the species suits a flat.
Chinchillas: Soft-Furred Acrobats
Chinchillas are lively, incredibly soft-furred rodents that need a tall, multi-level cage with platforms to leap between and a dust bath. They're nocturnal, dislike heat and humidity, and benefit from daily out-of-cage play in a chinchilla-proofed room. Delicate and fairly specialised, so not ideal for very young children, and costs run higher than most rodents.
Tarantulas: Fascinating Display Spiders
Tarantulas suit calm adult homes and are strictly "look, don't touch." They need a secure enclosure suited to whether the species is ground-dwelling or arboreal, infrequent feeding of insects, and very little cleaning. Many are shy; a bite is usually no worse than a bee sting but can affect those who are allergic, so research the species and check the rules first.
How to Choose the Right Small Pet
The right choice comes down to your space, budget, how much you want to handle your pet, and whether you're comfortable with live insect food. A few quick pointers:
- Tightest space and budget: isopods or springtails in a shoebox-sized tub, or small millipedes in a little more room - cheap, almost no upkeep.
- Want a hands-on companion: rats or guinea pigs (sociable, need company and time), or a calm rabbit.
- Out most of the day: low-interaction display species - isopods, millipedes, hissing cockroaches, leopard geckos, frogs or a tarantula.
- With supervised children: guinea pigs and rats are friendly and sturdy; inverts and reptiles work well as adult-led "family projects."
Whatever you choose, match the pet to your actual lifestyle rather than the other way round - the happiest setups are the ones where the care needs fit the time and space you really have. If time matters more to you than space, our guide to low-maintenance pets compares the options by the time and effort they take.
Frequently Asked Questions
What's the cheapest small pet to keep in a flat?
Isopods, springtails and small millipedes cost very little to keep: tiny enclosures, inexpensive food, and they rarely if ever need a vet. A basic isopod setup is little more than a tub, some substrate and leaf litter, and monthly costs are minimal.
Which small pets are best if I'm out most of the day?
Low-interaction display animals - isopods, millipedes, frogs, tarantulas or leopard geckos - need only brief daily checks and occasional feeding. Social mammals like rats, guinea pigs and rabbits can get lonely and are better for people who are home more.
Which small pets are good for children?
Guinea pigs, rats and calm rabbits are friendly and sturdy enough for supervised children. Invertebrates and reptiles work best as adult-led family projects, with grown-ups responsible for welfare and any vet care. No pet is truly maintenance-free.
How much space do small pets really need?
It varies hugely. Isopods are happy in a shoebox-sized container on a shelf, and small millipedes in a little more, about 30 by 30 cm for a small group of Thai Rainbows; rodents need a decent cage; reptiles need a vivarium of 60cm or more. Measure your space first and match the enclosure to it.
Do small pets smell or attract pests?
A clean, well-kept enclosure shouldn't smell. Odour usually means cleaning is overdue. Isopod, springtail and millipede setups, kept clean and not overfed, are practically odourless and don't attract pests - part of why they suit flats so well.
Leave a comment