About the species
A social rodent, the opposite of a hamster
The guinea pig is the opposite of a hamster when it comes to company - where a hamster typically lives alone, a guinea pig absolutely needs at least one companion of its own species. It's also active during the day rather than at night, which makes it easier to fit into a household's own rhythm.
Why it can't live alone
RSPCA guidance says a guinea pig shouldn't be kept alone unless a vet advises otherwise for health reasons - it's a strongly social animal that suffers from loneliness without a companion of its own kind. Even just two guinea pigs together need enough space to be able to move away from each other when they want to, so company doesn't just mean one more animal, it also means a bigger cage.
Why it isn't an ideal roommate for a rabbit
Pairing a rabbit with a guinea pig used to be common practice, but it isn't recommended today. The two species have different dietary needs and communicate differently, and a rabbit can injure a guinea pig by kicking, whether by accident or not - so the RSPCA advises keeping each species with its own kind, even when the intention was simply to give both some company.
Vitamin C the body can't make on its own
Like humans, a guinea pig can't produce vitamin C in its own body, so it must get it from food - otherwise it risks a deficiency disease called scurvy. It needs fresh, vitamin-C-rich vegetables every day, such as pepper or broccoli, with a supplement added if needed. This isn't a one-off dietary tweak; it's a permanent part of daily care.
An enclosure bigger than any hamster needs
Since it's a larger, social animal living in a pair or group, a guinea pig needs a noticeably bigger cage footprint than any hamster - enough for both (or more) animals to move, eat and rest freely without constantly being in each other's way. An ideal indoor temperature is around 17-20°C; RSPCA guidance notes that temperatures above 26°C risk heatstroke, while below 15°C the animal can get chilled too easily - so a guinea pig copes poorly with both heat and sudden temperature swings.
A vocal, expressive animal
A guinea pig vocalises far more than most small rodents - the distinctive 'wheeking' sound it makes when it expects food is one of the most recognisable noises among pets, and when excited it sometimes jumps and twists in the air, a behaviour known as 'popcorning.' These signs mark out an animal that's alert, engaged with its surroundings and responsive to its keeper.
A special caution around antibiotics
Some antibiotics, such as penicillin and related drugs, can disrupt a guinea pig's gut flora and trigger a severe, potentially fatal condition called enterotoxemia. Medication should always be prescribed by a vet experienced with exotic small mammals, never given based on guesswork or experience with other pets.
Who it suits
The guinea pig is considered one of the more approachable rodents for families, since it's active during the day, recognises its keepers and rarely bites. Even so, young children need adult supervision, since it's a delicate animal that must be picked up correctly, and the family needs to be ready from day one to house at least two guinea pigs together in a suitably spacious cage.
Temperament
friendly, sociable, vocal, diurnal, timid at first
Suitable for
families with children who can provide a pair and space
Living environment
a large ground-level cage (min. 0.7 m² for a pair), no upper levels
Grooming
unlimited hay, fresh vegetables and vitamin-C pellets, the company of at least one other, daily exercise
Pros & cons
Advantages of the species
friendly and diurnal, excellent for families with children, recognises its keepers
Things to consider
must never be kept alone, needs plenty of space, vitamin C is essential
Notes
It cannot synthesise vitamin C itself – it must come from the diet. A social animal never to be kept alone.
