When choosing a small pet, consider how much time you have to dedicate to the upkeep of your new companion. Many small mammals are physically easy to care for but require a lot of attention and affection.
Ferrets are intelligent and mischievous pets. Even a docile ferret can develop a habit of nipping, so you have to start training them early. Ferrets do require bathing and claw-trimming every few weeks. A ferret needs a heavy food dish and a water bottle for its cage. They need dry food that is high in protein and low in fiber, and eat several times a day. Ferrets live about 7 years; they can make good companions if you have plenty of patience and time to invest in them.
A lower-maintenance small pet is the fancy rat, which lives about 3 years. Rodents are very social and it's good to get a pair at a time; just make sure they are the same gender! Rats need grains and meat protein, which can be provided with dry dog food or mealworms. Domestic rats usually aren't aggressive; however, make sure you choose a rat from a reputable store or breeder so as not to get a bitter.
Guinea pigs, gerbils and hamsters are all gentle; low-maintenance small pets which live about 3 years. Gerbils and hamsters eat grains; hamsters also like fresh fruits and vegetables while gerbils will eat raisins and sunflower seeds. Guinea pigs eat hay and fresh vegetables (but no iceberg lettuce, raw beans or rhubarb). These pets like to be held and brushed with a baby's hairbrush; guinea pigs require nail-trimming occasionally. Gerbils need some sandbox sand to groom them. Like rats, guinea pigs, gerbils and hamsters are all social animals and do better in pairs.
Rabbits are also gentle and low-maintenance but they can live at least 10 years, so they are a serious commitment. Rabbits generally eat pellets and plenty of green vegetables; they will also eat hay. They like to be held but shouldn't be handled too much the first few days after purchasing, in order to adjust. Rabbits need plenty of out-of-cage exercise; many pet stores carry rabbit leashes, so you can keep your rabbit close by when outside.
Even small mammals need plenty of space. For rats, mice, hamsters, or gerbils, you will need at least a 10 gallon aquarium with a well-screened top. Guinea pigs and ferrets require at least two square feet of cage space per animal. For any small mammal, choose a cage with a solid bottom rather than a wire one, to prevent injuries to the paws. A rabbit needs a cage or hutch of at least 1 ½ feet wide by 2 ½ feet long, by 2 feet deep. Rabbits can be kept outside but make sure their hutch is well-sheltered. Small mammals need bedding for their homes; shredded paper or paper towels work best. Wood shavings work as well, but avoid cedar or pine shavings because of the oil they contain. Bedding needs to be changed about 3 times a week.
When choosing a small pet always be sure to look for alert, bright-eyed animals with smooth coats. If an animal also expresses interest in you, that's a good sign too.