▷What Do Mice Eat?

When one mentions the name, “mouse”, others are quick to have associations, both good and bad. They could think of grungy street mice that infest homes, or perhaps lab mice that are tested on. Or perhaps the loved children’s book, If You Give a Mouse a Cookie comes to mind. No matter the type of mouse or where it’s found, do they all share a common diet?

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What do mice eat?

It is well known that mice have spread to nearly all areas of the globe. Being extremely opportunistic in their feeding patterns, the mouse is an animal that can adapt to almost any habitat. As for what they eat worldwide, these small rodents consume fruits, seeds, and grains. Most mice are omnivorous, preying upon both meat and plants to survive. In times of desperation, mice have been known to even eat each other, but this isn’t common. Understanding the genus will help aid one in knowing why they eat what they do.

Collectively, mice belong to the genus Mus, which is Latin for “mouse”. They are known for their tapered muzzles, round ears, and slender bodies. There are 38 species in this genus that have a large distribution. Interestingly, mice and rats found anywhere between 1758 and the late 1800s were all considered species of Mus. It wasn’t until later on that these smaller individuals became the mice we know today.

Being so small, it is difficult to correctly identify how many mice the world has. Scientists believe that there is about 1 mouse to every 12 humans found within the bustling city of New York. Not all mice found on Earth have the same diets.

What Do Mice Eat in the Wild?

The menu items of a wild mouse vary greatly depending on where they live. Some live in the fields, other forests. And although the suburbs and cities of the world don’t seem like a “wild habitat”, they are not held in captivity. In order to fully understand the diet of a wild mouse, we must first break down where the animal is found.

Open Grasslands and Fields

Mice found in these habitats are typically characterized by their large black eyes, thin ears, and tails that are as long as their body. These traits make scurrying around and finding food an easy task. Species that dwell in the grasslands and fields are commonly the Deer mouse (Peromyscus maniculatus) and the Harvest mouse (Micromys minutus). These two species share the same dietary preferences.

Field and grassland dwelling mice are typically omnivores, meaning that they prey on both plants and meat. This includes seeds, fruits, berries, underground fungus, and various insects such as beetles or grasshoppers. They will adjust their diet depending on the season. When plant life is scarcer in the winter, these rodents will consume roots and tree bark as a dietary supplement. They are also known to sneak into homes in search of water and food.

Forest Mice

Unlike mice species found in the open grasslands, these individuals tend to be nocturnal, which is choosing to hunt actively during the evening. Forest mice are commonly found to be brown on the top with areas of lighter fur on the bottom. This allows them to camouflage amongst an array of predators, appearing as if they are simply the leaves in the forest. One such species found in forests is the White-footed mouse (Peromyscus leucopus) that have a similar diet to that of their field cousins.

Mice living amongst the trees and leaf litter are usually also omnivorous. The majority of their diet consists of seeds, berries, grains, fruits, and fungi. They also enjoy preying upon nuts and insects. Unlike mice living in the open grasslands, they will also incorporate leaves, wood, and bark into their diet.

Cities and Urban Structures

Those who picture these small rodents often think of them in big cities or other heavily impacted areas. It is no secret that mice have been able to adapt to the massive growth of the human population, capitalizing on the trash left behind. This brings us to the third habitat, the streets or urban dwelling inhabitants. The House mouse (Mus musculus) is by far the most common rodent pest found in most regions of the world.

When it comes to the diet of a mouse near humans, the question is not what it will eat, but what it won’t. Mice in these circumstances will eat a variety of plants, animals, and manmade items. As for the vegetation, they will focus mainly on leaves, roots, wood, seeds, nuts, grains and berries. Insects are also a popular menu choice for these rodents, mainly spiders and beetles. They prefer eating insects and seeds but will consume just about anything in urban settings, making them an incredibly opportunistic genus.

The House mouse will prey upon any food left out by humans. They will also eat items that seem undesirable. Such “meals” include glue and soap. These animals will also chew through plastic to get to food. This is what has made them into such unwanted guests. Their incredible sense of smell will lead them to a sustainable diet choice, regardless of the obstacle.

Prairies, Sand Dunes, and Deserts

Another worthy mention is a mouse that lives in harsher habitats. These mice need to find prey in areas with sandy soil; building burrows to combat the cruel elements. One such species is the Southern Grasshopper mouse (Onychomys torridus). Another name given to this animal is the Scorpion mouse, which alludes to the diet it can handle.

The majority of the diets found in desert-dwelling mice are various types of insects. For the Southern Grasshopper mouse, this includes grasshoppers, beetles and mainly scorpions. Humans equate the pain of the Arizona Scorpion to that of a hammer hitting your bare skin. To this species of mouse, this is just another meal. In fact, they feel no pain at all since the venom blocks the pain signal in the rodent.

The Southern Scorpion mouse will also eat smaller rodents. In addition to eating mostly meat, these animals do eat a small portion of vegetation. Scientists have determined that a mere 10 percent of their diet is reserved to seeds, plants, and vegetables. Taking this into consideration, they would technically be called an omnivore, but most regard them as carnivores due to their preferred choice of a meal.

Now that you better understand the complexity of a wild mouse’s diet, let’s focus on those individuals found in captivity.

What Do Lab Mice Eat?

The lab rat and mouse has been a lengthy discussion for years. Mice have similar genetic, biological and behavioral characteristics to that of humans, making them an ideal option for medical testing. For those living in laboratory settings, there must be a proper diet so that the individuals remain healthy.

Lab mice are generally fed a commercial mouse feed that hopes to meet all of the nutrient requirements. Among the ingredients found in these feeds are ground corn, oats, alfalfa, and dried beet pulp.

What Do Pet Mice Eat?

The most common species of mouse found in homes worldwide tend to be the House mouse (Mus musculus). And yes, that individual was mentioned earlier as one of the most common pests found in homes. They also make exceptional pets. Providing a balanced diet with variety is essential to keep a captive mouse both happy and healthy.

The diet of a pet mouse differs only slightly from that of a wild mouse. They are still typically omnivores, requiring both plants and vegetables. Most do not like to feed their household animals an insect, opting for powdered supplements instead. Included in these diets should be fresh vegetables, protein in either powder form or through insects, and mice food that will add anything that was lacking. Pet mice are highly prone to problems such as obesity, diarrhea and overgrown teeth that can be fixed with the proper nutrition. One of the biggest preventions is giving small amounts of mouse pellets that contain roughly 16 percent protein and 5 percent fat content. These, as with any food, should be given in moderation.

What Foods are Toxic to a Pet Mouse?

For the most part, mice will be able to handle a variety of foods. It is still important to understand what is toxic. Despite the fact that mice enjoy a wide range of plants and fruits, they cannot consume walnuts, raw beans, onions, raisins, and grapes. An owner should also refrain from giving their mouse wheat, lettuce, and corn. All of these foods will cause stomach problems.

What to Feed a Pet Baby Mouse?

Baby mice are known as pinkies, mainly because of their pink saturation. Females are able to produce about five to ten litters a year, with approximately six to eight pinkies in a litter. This makes raising a mouse in your home quite challenging. Oftentimes, people who have a pet mouse will not realize that they have a male and female, ending up with a large family over the course of a few weeks. But how do you take care of a baby mouse?

There are a variety of foods that will work for a baby mouse, some of which do not seem intuitive. Moistening commercial hamster food or kitten food is a good substitution for a baby mouse that does not have a nursing mother. Surprisingly, cooked peeled peas, soft carrots, and squash are also what a captive bred pinkie can endure. For younger pinkies, the best solution is kitten milk replacer that will provide them with the proper nutrition.