Mouse Basics

Basic Facts: Mice are social, sweet, gentle, creatures. They are nocturnal and they live for 1.5 to 2.5 years. The females are generally group animal and prefer to live with other mice in a large clean cage, with ample food. The males can sometimes live with other males, but usually prefer to be neutered to live with a group of females, or by themselves. If they start to fight or if they ever injure each other, they need to be separated. Make sure an extremely knowledgeable person double checks that they are the same sex, or get them spayed or neutered by an expert mouse surgeon if they are the opposite sex.

A mouse is a living creature, not a "learner" pet or a child’s toy. Adults are responsible for their health and safety. Mice should only be handled by gentle children who are old enough to understand how to be gentle, and only while the child is seated and under close adult supervision. When a mouse is woken up, or first wakes up, s/he may be cranky. Allow him/her a chance to perk up before handling, to avoid being nipped. Allow them to get to know and trust you. As they exit the cage, allow them to climb onto your flat palm at their own speed, and reward them with treats and kind words. This takes patience when they first meet you. They may try to dig through your hand or nip lightly to make sure that you are not food (make sure your hands are clean and do not smell like food). This light nipping is not the same as an aggression bite. When first handling a new mouse, do so over a soft surface, close to the ground in case they bite and you drop them accidentally. Always wash your hands before handling your mice to avoid transferring germs to them from the outside world.

Mice need temperatures between 65 and 85 degrees Fahrenheit at all times. In summer make sure the mice stay cool. Keep a frozen water bottle in the freezer to use as emergency cage air conditioning in case of power outages or AC malfunction. It’s a great idea to hang a thermometer on the outside of the mouse cage so that you can monitor temperature.

Food: Mice need a healthy diet to ensure a long healthy life. They should eat 50% washed veggies, fruits, proteins and grains (organic preferable) and 50% lab blocks (approximately 1/8 to ¼ cup daily). Lab blocks can be left accessible at all times, as most mice will not overeat them. When introducing new foods, do so slowly, one at a time, and check the mouse poop the following day to make sure their stools are solid. If they appear soft, discontinue all fresh foods until they are solid again. Mice will not eat all of the dry food every day, but they enjoy hiding it, and need excess to feel secure. Mice also benefit from a small amount of oat or timothy hay, especially when they are shedding. Lab blocks by Techlab, or other similar block-type food are better mouse foods. Mice should never get fruit seeds or pits as these contain arsenic. Mice should never have raw potatoes, yucca, onions, garlic, or food that is spoiled, slimy or moldy. If you wouldn’t eat it, they shouldn’t eat it either. If mice are ill or elderly, baby food sometimes gets them to eat. Fresh foods should be removed after a few hours and thrown away.

The mice need a plate or bowl made out of metal or sturdy ceramic, and it needs to be rinsed and dried out daily, with excess food thrown out (or to the birds).

Mice need fresh water every day. They need to have two bottles, because the bottles often become stuck and the mouse cannot go without water. Check the bottles once or twice per day by tapping on the ball to make sure water can easily come out. Also check the bedding under the bottles to make sure the bottles are not leaking. Weekly, the bowl and water bottles need to be washed with mild soap and rinsed well.

Mice should not have salt licks or mineral wheels.

Treats: Mice should never have store bought treats, (with the exception of treats from Oxbow), as they contain too much sugar. They shouldn’t have chocolate, candy, processed food, honey or soda ever. If mouse start to gain too much weight, cut back on people food and eliminate treats from their diet until the weight is lost, and then add back in moderately.

Housing: Mice are master climbers and escape artists. In spite of their small size, in nature they have a 5-mile range, so any housing we supply for them is going to be too small. Get the largest house you can possible afford and take care of. The minimum for a mouse house is 3 levels, 1 foot wide, by 2 feet long, by 2 feet high. Anything smaller is inhumane and will lead to cage aggression and biting. The cage sides should be sturdy metal wire or glass, not plastic or wood, since mice will happily chew out of a plastic or wood cage in a single night. Plastic toys and tubes can be used inside of a cage, but not as a means of containing them. Wires should be 1/4" apart maximum, and smaller for babies. The cage bottom should be solid, not bars, and all wire floor surfaces should be covered with cardboard, paper or placemats, to make cleaning easier and prevent injuries. Babies should have solid walls and not wires, as they will walk out from between the wires. The cage needs to be placed away from direct sunlight and sources of heat, which can cause the mice to overheat while they sleep, and away from drafts, which contribute to illness. Mice should not be kept in childrens’ bedrooms or anywhere accessible to children without adult supervision.

Exercise: Mice need exercise to stay healthy, just like humans. They need a wheel available at all times. The wheel must be at least 5" in diameter, with more than one for groups of mice. Larger wheels are also fine, as multiple mice can run on them together. The wheel must have a solid bottom or fine mesh, not rungs. Wheels with rungs break mouse legs and should never be used. Make sure the wheel will be easy to clean. A detachable wheel that is not connected to the cage is best. Mice are nocturnal, so check the wheel before you buy to make sure the sound of running will not disturb your sleep. Vegetable oil can be used to grease the joint to decrease squeaking or sounds.

Some mice will use a ball to explore and get exercise, but some refuse to use them. The ball should be about 6" in diameter. Make sure to always tape the ball shut with fresh tape or the mouse will escape. Mice can have daily ball time in 20-minute sessions. They will generally let you know when they are bored in the ball, because they will stop to eat, groom or sleep. When they do, take them out of the ball. Listen while your mouse is in the ball to make sure they are not trapped in a corner or by a cord. If there are children in the house, make absolutely sure that they never kick or throw the ball with the mouse in it, as this will kill the mouse. Young children should not handle the mouse ball ever. Mice may not like the ball, so never force them into it if they resist. Mice are highly curious and need mental exercise in addition to physical exercise, so they need to come out of their cage for a minimum of one hour every day for play and contact.

Bedding: Mice need a paper-based bedding or non-toxic bedding, such as Carefresh, Paper Shavings, SoftSorbent, Yesterdays News or Cagetech. They can also use rabbit food as bedding, as they will not eat it, and it tends to be non-allergenic. Cedar bedding is deadly. Pine bedding is potentially harmful. Aspen may be fine, but why chance it? Use safe bedding, about two to three inches deep. Mice love tissue, napkins and paper towels to make a cozy nest. In winter, provide extra bedding to ensure the mice stay warm enough, and consider putting towels or blankets around the bottom and sides of the cage to ensure warmth. The mice may pull these into the cage, so don’t use towels or blankets that are valuable. Never use any hamster fluff or cotton bedding material, as mice can ingest it and die. Boxes (without tape or plastic parts) or cardboard tubes make wonderful hideaways. The cage needs to be cleaned weekly, at a minimum and should be checked for moisture daily, and cleaned. Leaving mice in a filthy cage is animal cruelty. Don’t force your companion to live in filth. The cage should be cleaned only with white vinegar or mild soap and water, no harsh cleaners. If the mice have been ill, you can use bleach to disinfect, but only when the mouse is far enough away to be unaffected by the fumes. Mice are easily harmed by airborne chemical cleaners and other household chemicals. If you use them in your home, move the mice to a safe, fume-free area before using the chemicals. Some mice will use mouse litter boxes or the Hamster Potty. If you use them, make sure to use only Hamster Potty litter, Small Animal Litter by Kaytee or other safe bedding, never cat litter. If your mouse is ever dirty it is because s/he is sick or the cage is dirty. Mice clean themselves and should never be bathed. If they are ill and need to be cleaned, use a warm damp cloth and carefully dry the mouse with a soft towel. Keep them warm while they dry completely.

Toys and hideaways: Mice love to build amazing complex houses for themselves. Plastic pigloos, plastic tubes, plastic toys, wooden houses, cardboard boxes and tubes (plastic tape removed), are all wonderful to let them build. Give them a large variety of toys. Clean them weekly when the cage is cleaned and throw them away if they get dirty or splintered. Vary the toys to keep the mice entertained.

Chew toys: Mice need to wear down and sharpen their teeth constantly, so they need to have wire bars, dog biscuits or wooden chews available to chew on. Apple twigs, dog biscuits or willow chews seem the most popular.

Veterinary care: Mice deserve medical care, just as every other living being does. The "cost" of an animal should never determine its right to a long healthy life. Find a mouse vet before you need one. Often with mouse this will need to be a late night vet, because that is when a change in health or behavior is noticeable in these nocturnal animals. By the time a mouse seems ill, they are generally very ill and need prompt medical care. Never use Dritail or over-the-counter medicines, because a mouse with diarrhea should be rushed to a vet for rehydration (injection of Lactated Ringers solution) and medicine immediately, if s/he is to survive. Use the skin pinch test regularly to determine if your mouse needs rehydration. Gently pinch the skin between the shoulders and release it. If it stays up in a tent or retracts back to normal shape slowly the mouse is incredibly dehydrated. Keep unflavored children’s Pedialyte in the house in case of emergencies. If you can get your mouse to drink some on the way to the vet it may save the mouse’s life.

Do the pinch test when the mouse is healthy so you have something to compare it to in case your mouse gets sick. Be aware of your mouse’s normal eating, drinking, pooping, peeing, sleeping and activity patterns so that you can tell when they change. Inspect your mice on a weekly basis to help catch changes early. Common mice illnesses can include tumors, upper respiratory infections, allergies, malocclusion (overgrowth of the teeth), broken bones or sprains, mites/lice, cuts, abscesses, eye injury, and fungus. All of these conditions, including tumors, are treatable when caught early. If you feel like your mouse is not acting normally, trust your instincts and get to a vet immediately.