Guinea Pigs
Social, generally calm, rarely bite. Need same-sex company and a surprisingly large cage. Lifespan 5-7 years.
Rabbits
Can be affectionate but need careful handling and a lot of space, plus litter training is possible. Longer commitment — lifespan 8-12 years.
Hamsters
Mostly solitary, nocturnal, lower space needs than rabbits/guinea pigs but still more than typical starter cages provide. Shorter lifespan (2-3 years) makes them a smaller commitment.
Mice and Rats
Rats in particular are often more interactive and trainable than people expect, and are social — best kept in same-sex pairs or groups. Mice are quick and better suited to observing than heavy handling.
