Buzz
It is advisable to release adult wild mice back into their natural habitat as they can carry dangerous Hanta viruses along with fleas, ticks, and worms. Keeping wild mice in captivity is cruel because they will never lose their fear of humans, no matter how close you try to get to them. However, taking care of wild baby mice that cannot yet survive on their own is something worth doing. Mice raised by humans often lack basic survival skills needed in the wild as they grow, so if possible, you should continue to care for them. Mice raised in captivity are typically more affectionate, loyal, and intelligent compared to house mice.
Steps
Let the baby mouse stay with a surrogate mother
Attract the mother mouse out of the nest. If you have a house mouse mother taking care of baby mice of similar size to the abandoned wild baby mice, there's a good chance that the mother will care for the wild babies as well. You can lure the mother out of the nest and temporarily place her in a separate space so that she doesn't see you adding another baby mouse to her nest.
- Compared to raising them yourself, letting the wild baby mice stay with a surrogate mother is generally safer, especially for mice under 1.5 weeks old (around the time they first open their eyes).
Change the scent of wild baby mice. Be careful when using bedding material in the nest to rub it on the wild baby mice.
- Only use clean bedding – bedding with waste mixed in can harm the baby mice.
Place the wild baby mice with a litter of domestic mice. You should place the wild baby mice in the middle of the group, underneath the other mice. Try not to handle the group more than necessary, and be gentle while doing so.
Return the mother mouse to the cage. Place the mother mouse in the cage a little away from the nest, allowing her to find her babies on her own – do not force her to integrate with them immediately.
Do not disturb the litter of mice. Avoid lingering near the cage to observe or interfere with the mice. If the mother mouse becomes slightly upset, she may abandon the entire litter of baby mice.
- Be cautious as there is a risk that the mother may abandon the newly added wild baby mice (or even the whole litter).
- Be careful when introducing wild baby mice to the litter and avoid disturbing the mother and babies unless absolutely necessary.
- You will hear loud squeaking if something is wrong, so there is no need to stand right next to the cage to supervise.
Assist the mother mouse in feeding multiple wild baby mice. If you need the mother mouse to care for multiple wild baby mice at once, she may not have enough milk to feed them all. You should gently remove her from the nest a few times a day and place her in a separate cage. Then, feed the baby mice by hand, just like when you feed an abandoned baby mouse.
- If you notice a 'milk belly' (a white ring or visible white area in the mouse's belly, indicating milk in the stomach), the baby has received enough milk from the mother and no further assistance is needed.
- Check the baby mice a few times a day in the early days to ensure they are eating enough and not losing weight. Baby mice can lose weight very quickly and should be fed immediately if necessary.
Consider purchasing a mother mouse from a pet store. If you do not already have a mother mouse, you can buy a newly delivered mother along with her litter. For very young mice, having a mother to care for them increases their chances of survival more than hand-feeding them yourself.
- Keep in mind that moving the whole group of mice carries the risk of the mother abandoning her babies, so carefully weigh the decision before proceeding.
Rescuing an abandoned wild baby mouse
Ensure the nest has been abandoned. If you come across a nest of baby mice and cannot find the mother, it is possible that you accidentally startled her, causing her to run off, or she might be out for food. Leave the nest undisturbed and check back later – if the mother still hasn't returned, it's likely that she has abandoned her babies.
- Try to minimize contact with the baby mice, but don't worry excessively. Unlike birds, mice won't abandon their babies simply because they carry a human scent.
- After 4-6 hours, check the baby mice. If they don’t have a white ring around their bellies ('milk belly'), it means they haven't been fed properly. This suggests the mother may have died or abandoned the litter.
Contact a wildlife rescue center. If you find a wild baby mouse (or a nest of baby mice without a mother), you should contact a wildlife rescue center. Taking the baby mice to wildlife care experts gives them the best chance of survival. You can also take additional steps to help improve their survival chances.
- If there is no wildlife rescue center in your area, the second best option is to try hand-feeding the mice yourself.
- When calling the rescue center, ask them what their plans are for the mice. They might raise them or use them as food for other animals at the center. If you do not want the mice to be used as food, you will need to care for them yourself.
Quickly take a mouse attacked by a cat to a veterinarian. If a mouse has been attacked by a cat, the bacteria from the cat's mouth can cause a fatal blood infection. While you can take the mouse to a veterinarian for emergency care, the chances of survival are very low.
Help the baby mice feel comfortable. Line a box with clean, soft fabric. Be sure to trim any loose threads that could get caught on the mouse's legs.
- Always wash your hands after handling the mice. They may carry dangerous viruses, such as the highly contagious Hanta virus.
- If the baby mouse survives the first few days, you should transfer it to a glass or plastic cage with ventilation holes to prevent it from chewing through the cage.
Keep the baby mice warm. Baby mice need to stay warm, and the ideal temperature range is 27 - 38°C (you can use a thermometer to measure). You can place a low-setting heater, wrap it in a clean cloth, and place it under the box where the mouse is resting.
- Ensure the heater is not too hot – if it feels warm to the touch, let it cool for about a minute before placing the mouse on it.
- If you don't have a heater, you can use a box or a bag with warm rice. You will need to reheat or replace the rice as it cools down. Any container that can retain heat, such as a plastic bottle or thick zip-lock food bag, will work.
- A healthy baby mouse will be able to regulate its body temperature on its own by 2.5 weeks of age, as long as its cage is in a warm room.
Prepare a small syringe for feeding the baby mouse. An eye dropper is too large for feeding small mice. You should use a small syringe (without the needle). Pet stores often sell syringes with thin, curved tips designed specifically for small rodents.
Rehydrate the baby mouse. Unless you're sure the baby mouse has been with its mother for less than an hour, you should hydrate it before offering formula. Drop about 3-4 drops of unflavored electrolyte solution, like Pedialyte, directly into the mouse's mouth, wait about an hour, then proceed with formula feeding.
Hand-feeding wild baby mice
Determining the age of a mouse. To properly feed your mouse, it’s crucial to determine its age. Refer to a diagram showing mice at different developmental stages and compare the size of your mouse to see which image it matches.
- A mouse starts growing fur around 3-5 days old.
- At 10-14 days old, the mouse’s eyes open.
- Once the eyes are open, they enter the 'jumping' phase, where healthy young mice will jump vigorously and are very difficult to catch.
Be cautious to prevent drowning. Feeding or giving water to a mouse can cause it to drown, even with a small amount of liquid entering its lungs. If you see bubbles escaping from the mouse's mouth while feeding it, this may indicate drowning.
- Keep the mouse upright (vertically) when feeding it – never feed it while lying down like an infant.
- If you notice bubbles at the mouse's mouth, quickly turn it upside down (with its tail facing up and head down) to prevent further liquid from entering its lungs.
- Unfortunately, baby mice have a low survival rate if they drown. Slightly older mice have a slim chance of surviving if you act fast and turn them upside down.
Feed baby mice according to their age. The actual age of abandoned mice may be older than their appearance due to insufficient care and nutrition. Feed the mice based on your observations and their corresponding age.
- Newborn mice need to be fed every 1-2 hours to survive, day and night. You'll need to wake up during the night to feed them.
- Once the mice open their eyes (around two weeks old), you can extend the feeding interval to 3-4 hours.
Feed baby mice according to their body size. You should feed baby mice approximately 0.5 cc for each gram of their body weight. For instance, a 10g mouse needs about 0.5 cc per feeding. Use a syringe with clear cc markings for feeding.
- Feed them kitten formula mixed with water, as baby mice cannot digest undiluted formula.
- Hold the mouse upright during feeding to prevent the formula from entering its lungs. Place your hand around its waist (where the human waist would be) and ensure its head faces up and its back legs face down. The mouse's front legs can rest in your hand depending on the mouse and hand size.
- Administer the formula into the corner of the mouse’s mouth.
- Be careful not to spill formula into the mouse’s nose – this could cause suffocation. You can gently wipe its face with a cotton swab after each feeding to ensure its nose remains clear.
- If the mouse seems to be losing weight, try offering more formula.
- Never force feed the mouse – allow it to feed slowly.
- If the mouse is too small, use a clean, new fine-tipped paintbrush instead of a syringe. Dip the brush into the formula and gently apply it to the mouse’s mouth.
Stimulate the mouse to urinate. Baby mice will not urinate on their own and can die from waste accumulation if not stimulated. After feeding, gently rub a cotton swab soaked in warm water around the mouse’s belly and anus until it urinates.
- Avoid over-rubbing to prevent skin irritation.
- If the mouse doesn’t urinate after a few minutes, let it rest and try again after half an hour.
Feed older mice solid food. Once the baby mice open their eyes and are in good health, you can start introducing solid food in addition to formula milk. Continue giving the mice milk until they are around to 4 weeks old.
- Suitable solid foods for mice include: pre-made food for rodents (hamster food is ideal), cooked rice (mice generally prefer white rice over brown rice), baby food, and kitten food.
Provide older mice with a water bottle. Mice that have opened their eyes can start drinking water from a rodent water bottle. Hang the bottle by the cage so the mice can easily reach the nozzle. Allow them to use the bottle freely – it's okay if they don't use it at first.
- Do not allow mice to drink from a bowl – they are very prone to drowning.
Things you will need
- Kitten formula, such as KMR
- Small syringe (without a needle)
- Small box with ventilation holes for newborn mice (those who have not opened their eyes yet)
- A small aquarium or rodent cage for housing older mice (those who have opened their eyes)
- Bed lining materials (such as unscented toilet paper, napkins, clean rags, or paper towels)
- Heating pad
- Cotton swabs
