Prevention Tips
Practical steps and tips on how to prevent mice infesting your property
Types of Mice
There are hundreds of types of mice found in Ireland, but a much smaller number are considered pests, which pose a threat to homes and businesses.
The top 3 pest mice you are likely to encounter include the House Mouse, Field Mouse and the Yellow Necked Field Mouse.
Field Mouse
(Apodemus slvaticus)
Field mice rarely venture into inhabited buildings but in the winter months, they will go into outhouses and sheds where fruit and vegetables are stored.
As such, field mice are a bigger threat to businesses, in particular farming and agriculture.
Appearance
- Size: adult head and body 80 – 100mm in length; Tail 70 – 90mm.
- Weight: Male can weigh 25g, and the female 20g.
- Sandy / orange brown fur on the head and back.
- Yellowish fur on the flanks and white on the belly.
- There is usually a small streak of yellow on the chest.
Life cycle and habits of a Field Mouse
Life Cycle
- Their lifespan averages two to three months, but they can survive as much as 20 months in the wild, or two or more years in captivity.
- Breeding seasons are March/April to October/November and gestation lasts approximately 25 days. They grow their first fur after six days; their eyes open after 16; and they are weaned at around 18 days old.
- Survival of the young and adults is poor during the first half of the breeding season as adult males can be aggressive towards one another and to the young, who are then driven from the nest.
Habits
- They eat a high proportion of the seed crop of trees such as oak, beech, ash, lime, hawthorn and sycamore.
- Small snails and insects are particularly important sources of food in late spring and early summer when seeds are less available.
- They also eat apples and will attack newly planted legume seeds.
House Mouse
(Mus domesticus)
It is wrongly believed that mice are only a problem in the winter time.
House mice are active all year round, which means you could find them invading your home or business at any time.
Appearance
- Size: 7 – 9.5cm in length, with a tail around the same length.
- Weight: 12 – 30g.
- Their relatively small feet & head and large eyes & ears distinguish them from a young brown rat (Rattus norvegicus).
Life cycle and habits of a House Mouse
Life Cycle
- 4 – 16 young per litter; 7 – 8 litters a year.
- Gestation period of about 3 weeks.
- 8 – 12 weeks from birth to sexual maturity.
Habits
- Usually ground living and burrowing, but often climbs.
- Preferred food is cereals.
- Will eat around 3g of food a day and can survive without any additional water. They will drink up to 3ml a day if their diet is particularly dry.
Yellow Necked Field Mouse
(Apodemus Flavicollis)
Yellow necked field mice are mostly a threat in rural areas. In homes they pose a fire risk as they are known to chew threw electrical wiring.
Appearance
- Size: adult head and body: 95 to 120 mm in length; tail 75 – 110mm.
- Weight: ranges between 14 and 45g.
- Brown fur on their backs and white on the underside with a distinctive complete band of yellow fur around the neck.
- Large ears, protruding eyes and a long tail.
Life cycle and habits of a Yellow Necked Field Mouse
Life Cycle
- Breeding occurs from March or April until October, with gestation taking 25 or 26 days.
- Young are fully weaned after about 18 days and usually start to breed the year following their birth.
- Most mice do not survive longer than 12 months.
Habits
- They can spoil or consume stored food or interfere with electrical wiring.
- They prefer mature broad-leafed woodland and habitats such as hedges, rural gardens and buildings.
- They are more likely to enter buildings than wood mice (Apodemus sylvaticus).