Rat Species

There are two main types of rats that cause concern in Singapore. The Brown Rat (sewer rat) and the Black Rat (roof rat) are commonly found in both private homes and business property.

Black Rat (roof rat)

(Rattus rattus)

Black rats can be found in coastal towns and in many urban environments across Singapore.

Appearance

  • The black rat is between 16–24cm in length, with a tail longer than the head and body.
  • It grows to between 150–200g in weight.
  • They have a pointed nose, large ears and a slender body.

Life cycle

  • Black rats produce 5–10 young per litter, and have between 3–6 litters a year.
  • The gestation period is about 3 weeks.
  • It only takes between 12–16 weeks from birth for them to reach sexual maturity.

Habits

  • They are incredibly agile and very good climbers.
  • Their preferred food is moist fruits. Black Rats will eat around 15g of food a day and drink 15ml.

Brown Rat

(Rattus norvegicus)

Brown rats usually prefer ground living and burrowing, but sometimes they can be known to climb.

Appearance

  • The brown 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).

Life cycle

  • 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.

Habits

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

House Mouse

(Mus musculus)

Where is house mouse found? Capable of surviving nearly any environment - small size, high adaptability + needs extremely small amount of food and space.

Appearance

  • 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)

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.