House Mouse
Mus domesticus
Appearance
- 2 3/4″ – 3 3/4″ in length, with a tail around the same length.
- 12 – 30g in weight.
- Their relatively small feet & head and large eyes & ears distinguish them from a young brown rat (Rattus norvegicus).
Lifecycle
- 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.
Norway Rat
Rattus norvegicus
Appearance
- Up to 15 3/4″ in length, with a tail shorter than the head and body.
- 350 – 500g in weight.
- Blunt nose, small ears and a thicker body when compared to the Black Rat (Rattus rattus).
Lifecycle
- 7 – 8 young per litter; 3 – 6 litters a year.
- Gestation period of about 3 weeks.
- 10 – 12 weeks from birth to sexual maturity.
Habits
- Usually ground living and burrowing, but sometimes climbs. The only species to occur in sewers in Australia.
- Preferred food is cereals.
- Will eat around 30g of food a day and drink 60ml
Roof Rat
Rattus rattus
Appearance
- 6 3/8″ – 9 7/16″ in length, with a tail longer than the head and body.
- 150 – 200g in weight.
- Pointed nose, large ears and a slender body when compared to the Brown Rat (Rattus norvegicus).
Lifecycle
- 5 – 10 young per litter; 3 – 6 litters a year.
- Gestation period of about 3 weeks.
- 12 – 16 weeks from birth to sexual maturity.
Habits
- Quite Rare. Appearance confined mainly to ports.
- Often climbs, agile, rarely burrowing and rarely outdoors in Australia.
- Preferred food is moist fruits.
- Will eat around 15g of food a day and drink 15ml.
Field Mouse
Apodemus sylvaticus
Appearance
- Adults: Head and body 3 1/8″ – 4″ ; Tail 2 3/4″ – 3 1/2″ .
- Male can weigh 25g, and the female 20g.
- They have fur which is sandy / orange brown on the head and back, yellowish on the flanks and white on the belly. There is usually a small streak of yellow on the chest.
Lifecycle
- 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.
- The 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.