Norway Rat:
General Description
- Distribution: Asian in origin and worldwide in distribution, and quickly adapt to the environment.
- General Appearance: Large, robust
- Adult size: Large
- Body weight: 200-500g,
- Length (nose to the tip of tail): 18-27 cm
- Length of Tail: 13-21 cm
- Snout: blunt
- Ears: small, covered with short hairs; do not reach eyes
- Eyes: Small
- Tail: dark above, pale beneath
- Fur: brown with scattered black; venter gray to yellow-white; shaggy
- Droppings: capsule-shaped, 2cm
The difference between the climbing or roof rat, Rattus rattus and the Norway or brown rat, Rattus norvegicus.
Life Cycle and Common Characteristics
- Norway rats prefer moist environments (cellars, streams, stores, warehouses, and mills).
- considered an excellent swimmer.
- The life cycle of rodents is no more than 1–1.5 years in natural conditions, and females live longer than males.
- Norway rats prefer to live in groups of small families or large groups.
- Breed throughout the year, beginning a period of sexual activity after 3-5 months of birth, a pregnancy lasting 21–25 days, an average female pregnancy of 8–12 short weeks, and a medium repeat pregnancy of 5–10 times a year.
- The life cycle has significantly affected the availability of food.
Comparisons of the reproduction characteristics among the three commensal rodents.
| House Mouse | Roof Rat | Norway Rat | Characteristic |
| 42 Day | 68 Day | 75 Day | Days to Maturity |
| 19-21 Day | 20-22 Day | 22-24 Day | Gestation Period |
| 5.8 | 6.2 | 8.8 | Young per Litter |
| 7.67 | 5.42 | 4.32 | Litters per year |
| 44.6 | 33.6 | 38.00 | Young / fenale/year |
| 1>5-2 Month | 2-3 month | 2-3 month | Age at Mating |
| Year-Long | Spring & Fall | Spring & Fall | Breeding Season |
Comparisons of the characteristic of growth and development of commensal rodents.
| House Mouse | Roof Rat | Norway Rat | Charcater |
| 19-21 day | 20-22 day | 22-24 day | Gestation Period |
| 0.8-1.5 g | 4-5 g | 5-6.5 g | Weight at Birth |
| Without pink hair | Without pink hair | Without pink hair | Hair Color at Birth |
| 3-4 day | 6 day | 3-4 day | Opening the Ear |
| 11-14 day | 14-15 day | 16 day | Opening of the Eye |
| 9-10 day | 10 day | 10 day | Appearance of Lower Incisors |
| 7-8 يوم
7-8 day |
11 day | 11 day | Appearance of Upper Incisors |
| 42 day | 68 day | 75 day | Day to Maturity of Females |
| 1 Year | 1 Year | 1 Year | Length of Life |
