• The norway rat is up to 40 cm in length, with a tail shorter than the head and body.
  • It grows up to between 350–500g in weight.
  • It has a blunt nose, small ears and a thicker body when compared to the Black Rat (Rattus rattus).


  • Rats have 7–8 young per litter, and between 3–6 litters a year.
  • The gestation period is about 3 weeks.
  • It only takes 10–12 weeks from birth to reach sexual maturity.


  • Preferred food is cereals, although they are omnivorous.
  • They will eat around 30g of food a day and drink 60ml.