The most common rodents kept as household pets are hamsters, gerbils, fancy rats, fancy mice, common degus, common chinchillas, and guinea pigs.
Some rodents are prohibited from being kept as pets in certain areas for being invasive. California, Hawaii, and New Zeeland have strict regulations to protect their native environments and agricultural operations.

Circadian rhythm is the name given to the body’s 24-hour “internal clock.” This internal clock controls the body’s sleep-wake cycle.
Crepuscular: active primarily during the twilight period.
Diurnal: active during the daytime.
Nocturnal: active during the night and sleeping during the day.
Types of rodents as pets
Guinea pigs: Perhaps been kept the longest as pets among rodents. Their diet consists of grass hay and food pellets. Females become fertile at four weeks and may produce as many as four to five litters a year. They live to be around 4 to 5 years old.
Fancy mouse: Their sense of smell is highly developed, and many mice can recognize if another mouse is part of their family group based on smell alone. Female mice may have up to 15 litters a year, due to their ability to become pregnant again within 24 hours of giving birth. The average litter size is 10 to 12 pups who are born deaf and blind. The litter will resemble small adult mice within 2 weeks.
Fancy rats: Whereas mice enjoy independence, domesticated rats rather enjoy the company of their owner. Female rats may become pregnant as early as five weeks old, producing a litter of about 8 young each time, and are able to become pregnant after 24 hours. Domestic rats live slightly longer than wild rats, with a life span of around 2 years.
Hamsters: Syrian and dwarf hamsters are very popular pets. Currently, 18 different species of hamsters exist. They produce two to four liters a year. Domestic hamsters which are caged together will act aggressively towards one another as they get older, usually fatally.
Gerbils: They became established in the pet industry in 1964. Gerbils are prohibited in California. They have an average lifespan of two to four years. Gerbils are naturally curious, social, and nonviolent, making them more suitable for children than most pocket pets.
Degus: They become popular pets, though until recently they were seldom found in pet shops. Degus are prohibited in California. They require constant access to hay, and small amounts of pellets and leafy vegetables. Avoid fruits and vegetables high in sugar content as they are prone to two types of diabetes.
Chinchillas: They are popular pets but require a lot of care. Chinchillas like to have a companion and can live more than 10 years. They can breed at 6 to 9 months of age and can have up to 3 litters. Their diet consists of grass, hay, and grass-based chinchilla pellets. They can eat small amounts of dried fruit and root vegetables as treats, but too large an amount can lead to obesity.

Featured image: Courtesy Roulla Janse van Rensburg
Content creator: Petrus A. van Tonder
Reference: Wikipedia