- 7 – 9.5cm 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).
- 4 – 16 young per litter; 7 – 8 litters a year.
- Gestation period of about 3 weeks.
- 8 – 12 weeks from birth to sexual maturity.
- 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.