Field Mice – Habitat, Identification, Habits, and Removal Remedies
The field mouse is a close relative of the commonly found house mouse. They are also known as Voles. And no they are not the same as moles! Field mice are also known as meadow mice, meadow moles and ground moles in some parts of Australia, Canada, and the US. These pesky rodents belong to the Microtus genus family. It is less common to find field mice in a house. Their infestation is more outdoors than indoors, but neglecting it can lead to severe problems.
How do I identify field mice?
For that, you need to know what do field mice look like? As per the research conducted by Penn State Extension, field mice or voles are small, chubby, ground-dwelling rodents. They have a stout body, little legs, and short tails. The size of a field mouse is approximately 5 to 7 inches depending upon their species. With good living conditions, these mice may even reach a length of almost 8 inches. They weigh approximately 3 to 4 ½ ounces. They have small black eyes. Their underfur is usually dense often hiding their ears behind it. Their fur is covered with thick guard hair. Most meadow mice are brown or gray in color. Their underbelly is usually grey while feet are brownish in color. Field mice may also have several color variations. Baby voles are usually grey in color.
Which are the different types and species of field mice?
There are more than 20 types of field mice in the United States. Some of the more commonly found species are:
Meadow Vole: It is the most widely spread vole species in the United States.
Prairie Vole: It is the most common vole in prairie habitats.
Long-tailed Vole: The long-tailed vole can be differentiated from other field mice species by the length of its tail. Its exceptional tail makes up more than 30% of its total length.
Woodland or Pine Vole: The pine vole is a little vole.
Mountain or Montane Vole: The montane field mouse is identified by its feet which are typically silvery-grayish in color and have whitish underparts.
Oregon Vole: The Oregon vole can be distinguished with its distinct underparts that are darkish in color, with shades ranging from white to yellow.
California Vole: The California vole has a unique ochre olive to dark brown colored fur.
Red-Backed Vole and the rock vole are generally found in mountainous regions.
Dr. Alan T. Eaton who is a Specialist in Entomology and an Extension Professor at the University of New Hampshire has explained the vital difference between different types of field mice in his extensive research.
What is the difference between a field mouse and a house mouse?
It is particularly tricky to differentiate the field mouse and the house mouse. Both look very similar to each other and identifying can be very challenging for most people. University of Connecticut’s College of Agriculture, Health and Natural Resources has studied different rodents in detail and has highlighted vital differences between them.
A telltale sign to differentiate both is the difference in the length of their tails. House mice have long tails that may extend up to approximately half their body length, while field mice have short tails. Some other differences between a field mouse and house mouse are:
The field mouse has eyes and ears smaller than the house mouse.
The field mouse has a rounded snout while the house mouse has a comparatively pointed snout.
Differentiating Voles and Moles
A lot of times people mistake voles to be moles, not just due to their similar names but also due to their similar appearance. Since both field mice and moles are rarely seen, it becomes extremely difficult for humans to differentiate one from the other. To an untrained eye, it is very difficult to differentiate the field mouse and the mole. Researchers at the University of Maryland, have enlisted easy ways of differentiating between the field mice and moles.
One of the biggest distinguishing factors between moles and field mice is the size of their teeth. While field mice do not have large front teeth, moles typically have large front teeth.
The field mouse has visible ears while the mole’s ears are very tiny and almost invisible.
Moles have larger feet that are close to the body while field mice have shorter legs.
Even the food habits of moles are different from field mice. While field mice prefer to eat green vegetation, the mole is primarily an insectivore and feed on earthworms and insects.
The lifespan of field mice
How long do the field mice live? The lifespan of field mice is really short, ranging from 2 to 16 months. With good living conditions, the lifespan of field mice may sometimes extend to 20-24 months.
Female field mice mature in about 7 to 8 weeks after birth. According to Professor Joanna Gliwicz of the University of Warsaw, Poland the approximate gestation period is about 3 to 4 weeks. Female voles living in the wild may have 1 to 5 litters per year. In laboratories, they have produced up to 17 litters per year. Litter sizes averages from 3-6 per litter. Sometimes they may give birth to 11 babies.
There is heavy aggression from adult males towards the young ones, so survival rates of babies is very poor. Only 10% of newborn voles survive after the first week of their life.
Field mice may breed throughout the year depending on their location. The peak breeding period is usually in the spring (March/April) followed by a second, smaller breeding season in the fall (October/November)
Habitat—where do field mice live?
Depending on their types, field mice are able to survive in different habitats: ranging from forests and savannas to forests, prairies, and dense grasslands. Some species of field mice are also found in humid swamps, and even freezing arctic areas.
Research conducted by the University of Idaho states that field mice prefer to live in areas of dense ground cover. Field mouse habitat is typically areas of thick vegetation, greater than 6 inches in height, covered with leaves or tree branches, or snow covers as it provides effective protection from predators. They prefer to live in orchards, windbreaks, crop fields, lawns, gardens, hay fields, grass fields, and pasture as they are good sources of food.
These mice are semi-fossorial. They dislike crossing bare ground and prefer cover when feeding. They build many shallow tunnels and runways with burrow entrances. Field mouse burrow entrances are never bigger than 3 inches. Voles build underground nests from grass, stems, and leaves. Their nests are circular structures about 6 to 8 inches in diameter. They build a nest on the surface of the ground, usually with some form of covers like wooden logs, old boards, or used metal. During winter, they make temporary nests in deep snow, which are vacated with the advent of spring when the snow melts.
Food Habits – What do field mice eat?
Field mice can eat nearly their own body weight daily. Meadow mice are mostly herbivores. What does a field mouse eat? According to the PGC (Pennsylvania Game Commission), voles are mostly vegetarian. They eat a wide variety of plants, nuts, fruits, leaves, and grass. Their most favorite food is grass, flowering plants, and forbs. Field mice eating habits during summer and early autumn are to store seeds, tubers, berries, fungi bulbs, and rhizomes in their tunnels. During late fall and winter field, mice may occasionally eat bark. They may also eat grain crops. Some types of these mice are omnivores and may also eat snails, insects, and animal remains. Pine voles feed on plant roots and crowns.
Behavior Habits– Are field mice nocturnal?
Depending on the type of field mice, they may be nocturnal or diurnal. Some of them are active through the day and night, with peak activity taking place mostly around dawn and dusk. They do not hibernate.
Field mice are very fast rodents. They can run at a speed of up to 6 miles per hour. Many voles are excellent swimmers. The water vole which lives near the water can also escape from predators by swimming and diving. Some voles can also survive tides and flooding due to their strong swimming skills.
Most voles are poor climbers. The meadow vole is usually seen at ground level as it does not climb walls, roofs or attics, etc. like other mice. According to the Nevada Department of Agriculture, the long-tailed vole is a very good climber.
Signs of field mouse infestation—how do I find the field mice in my garden?
The usual signs of girdling and gnawing marks are not enough in determining field mouse infestation in your surroundings. The PMRA (Pest Management Regulatory Agency, Canada) has listed the following symptoms of field mice infestation.
The most common and easy to identy sign of field mice is their far-reaching surface runway system with several burrow openings.
Runways created by voles are usually about 1 to 2 inches wide.
Typical vole infestation can also be identified by signs of vegetation that has been clipped near to the ground.
The runways are also littered by small mounds of field mice feces typically brownish in color and little pieces of vegetation.
Field mice infestation can also be identified by tree barks that have been removed completely around the base of a tree.
Field mice leave behind small holes in the ground, usually near the base of trees and shrubs.
Damage caused by the field mouse
Voles can cause serious damage to your garden and outdoor landscape. According to UCIPM (University of California Integrated Pest Management Program), field mice feed on a wide variety of garden plants like cabbage, beet, artichoke, beet, carrots, celery, lettuce, tomato, turnips, and Brussels sprouts. They also can spoil lawns, turf and other flowery plants. They nibble the bark of fruit trees like apple, olive, avocado, and cherry causing serious damage to them. Decorative trees are also damaged by voles. Since field mice eat field crops they are a serious threat to crop cultivation also. Crop irrigation systems may also be damaged when they build widespread runways and tunnel systems. Voles also can destroy golfing greens, parks and greenhouses.
Hazards of field mice in the house—do field mice spread diseases?
Are field mice dangerous? Research conducted by the Resources explains that field mice are not a major source of public health hazard due to limited contact with humans. However, they may carry disease organisms, such as plague (Yersinia pestis) and tularemia (Francisillatularensis).
Winning the battle against field mice – how to control field mice?
Rutgers, the State University of New Jersey has enumerated simple steps towards controlling the field mice population around you:
Decrease the availability of food and cover by removing wild plants, weeds, and crop droppings in your home, farm, garden, or stable.
Regular mowing of lawn and turf helps to keep field mice away as it removes the cover needed by them during crossings.
Destroy runways and tunnels by frequently tilling the garden and surroundings.
Wood piles, brush piles, and compost piles should be properly covered and should be arranged away from lawn areas.
In order to keep voles out of the garden, wire fences that are at least 12 inches above the ground with a small mesh size may be set up.
Traps and Repellents that work against Field Mice
Traps such as mouse snap traps, box traps, and multiple-catch traps are useful for capturing field mice. Traps should be installed near burrow openings and runways. Bait of the vole’s favorite food — apple slices often used. Even peanut butter may be used as successful bait. Natural repellents made out of capsaicin from hot chili peppers may be used as a short-term solution to field mice. Field mice are very vulnerable to predators as they are active through the day. Installing raptor perches in the area may promote birds of prey to hunt field mice.
As with most rodent control programs, “an ounce of prevention” rule goes a long way in keeping field mice away. Prevention is definitely better than cure when you are dealing with the ubiquitous field mice.