Brown Rats (Rattus Norvegicus) are more efficient at breeding than rabbits and are capable of birthing a large scale infestation from a single pair given that the conditions suited for rapid growth are good (which are subject to a number of factors). This means that there would be no seasonal intervals and as soon as a female has given birth she can be ready to conceive immediately though those rearing factors regarding conditions will be taken into account by female rats. If conditions are less favourable, then breeding may take place in the summer and autumn months.
Brown Rats are capable of giving birth approximately every 3 – 4 weeks meaning that populations may rapidly grow out of control and may only stop or decrease if the availability of resources is out weighed by the population which depends on the premises and its purpose, though resources may provide sustainability ensuring their harbourage. Other than that, a plan of implemented pest control management between the occupants and a pest controller may need to come into play ultimately altering their reproductive pattern if a permanent resolution isn’t possible.
Identifying a Infestation
There are a number of ways the presence of rats or an infestation can be identified within a premises:
The easiest way of determining an infestation is by multiple or continuous Sightings of Rats throughout a premises or working environment. A thorough check should be carried out by if not yourself, than a specialist if excessive sightings have been made.
Rats consistently defecate whilst they manoeuvre on the surfaces of a premise, and this will usually look like Large Black or Brown Pellets (the size of raisins) in rooms on any surface. They also urinate as they manoeuvre though urine stains can be mistaken for water marks.
Internally, this may be in the form of Large Circular Holes on surfaces, Gnaw Marks on material surfaces and Strewn Plastic or Fabric similar to confetti. Damage to foodstuffs and their packings may also be present which resemble the remains of consumed food peculiarly discarded.
Smell of Presence
If an infestation is of a certain severity, then the Smell of their Fur and Urine may become apparent and overwhelming. In a worst case scenario the Smell of a Dead Rat or Rats may also be present to which in those circumstances you most certainly know that rodents have invaded your premises.
Identifying an Adult Rat is not at all difficult as their physical appearance is five times the size of mice displaying the familiar traits of four legs, two sets of incisor teeth (top and bottom of mouth) and either grey or brown fur with a thick large scaled tail. They are approximately 200 – 250mm in length (though can be larger) and are found in a variety of premises that have a number of resources to offer. An infantile rat would resemble an adult mouse though its head and paws would look largely out of proportion.
There is another species of rat which may be mistaken for a sewer rat named:
The Black Rat / Ship Rat (Rattus Rattus) – may reside in trees, port warehouses at heights, ground level of urban and rural habitats. Unlike Brown Rats, Black Rats are extremely good climbers measuring approximately 150 – 200mm in length (though can be larger) and have a black fur with a longer thinner tail.