Small rodents are popular pets, as they are generally easy to care for. Specific behavior depends on species.
Gerbils are active, hardy creatures that can be territorial; thus, they are best caged singly. They should never be picked up by their tails, as tail skin can slough easily. They are desert animals that drink very small quantities of water.
Hamsters tend to be less active and easier to hold; however, they can jump, are nocturnal (active at night), and may bite if awakened suddenly. Like gerbils, they should be kept singly. Hamsters tend to develop stress-related diseases, such as gastrointestinal problems, more easily than some of the other small rodents. They also do not tolerate hot, humid conditions and need to be kept relatively cool. At very low temperatures, they go into a deep, hibernating sleep. Hamsters generally like to exercise on wheels and may escape their cages by chewing through plastic. All small rodents’ incisor teeth grow continuously; thus, they should be provided with safe, wooden toys on which to chew.
Mice are very quick moving, fairly disease-resistant, nocturnal animals that tend not to bite as much as some of the other smaller rodents. Male mice may fight, but females can be housed together successfully.
Small rodents may be housed in plastic or wire cages or in aquariums. Aquariums are more escape proof but can be poorly ventilated and difficult to clean. Aquariums must be covered with mesh tops that firmly attach to the tank to prevent escape.
Plastic-walled cages may be easier to clean but also may be poorly ventilated. If wire cages are used, the spaces between wire mesh should not be so wide that small rodent feet can get caught. Ideally, the cage bottom should have a plastic tray that slides out easily for cleaning.
Bedding should be made from recycled paper products, newspaper, or paper towels. Wood shavings and corncob are not recommended, as they may be dusty, allergenic, and difficult to keep clean. Food may be offered in small, heavy, shallow dishes; overhead hoppers affixed to cage walls also may be used to prevent food hoarding and food contamination with feces. Water should be given in small sipper bottles hung inside the cage. Care should be taken to ensure that the sipper tubes in these bottles don’t get blocked with air bubbles or debris and that bottles don’t empty out from leaking.
Many small rodents, especially hamsters, love to run on exercise wheels. Longhaired hamsters’ coats should be trimmed short to ensure they don’t get caught in wheels, and wheels should not have sharp edges that cause injury. Wheels should be solid plastic, with no slots or holes, to prevent feet and tails from getting caught. Small rodents often enjoy rolling around inside plastic spherical exercise balls but should be kept away from stairways and small children when inside these balls.
Plastic mazes and tunnels can also be fun for small rodents. These pets must be taken out their cages daily and handled to socialize them and to provide environmental stimulation.
The nutritional requirements of most small rodents are similar. In general, commercially available formulated diets, either in block or pelleted form, are recommended for small rodents. Feeding all-seed diets or seed-pellet combinations are not recommended, as most small rodents will select out the high-fat seeds, ignoring the more nutritious pellets, leading to obesity, vitamin/mineral deficiency, and other nutritional problems, such as osteoporosis.
Small amounts of fresh vegetables and fruit may also be offered daily. Gradual introduction of any new food is essential to prevent starvation.
All small rodents should be examined by an exotic animal veterinarian initially after purchase and annually to ensure they are healthy. They should receive a complete physical examination, as well as a fecal analysis to check for parasites. Species-specific diet and husbandry requirements should be reviewed. Proper preventative medicine can help avoid the development of disease and ensure the lifelong health of your small rodent.