Rattus rattus (House Rat, Black Rat, Roof Rat, Plague Rat)By far the most common Rat encountered in homes and structures. Growing upto half a kg in weight and half a metre in length from nose to tail. The rat illustrated is nearly half a metre long and recently caught in Ngaio, Wellington.
Usually found in the ceilings, walls and basement areas of dwellings, often moving in at the beginning of winter or in cold snaps and staying over and breeding in the spring.
If left untreated rat popultaions will increase rapidlyu and also do severe damge to your home, insulation, wiring, plumbing and food supplies. They also feed on native birds, nestlings and eggs. Access to a typical residence can be by any of the following,
Trees in near proximity to the roofline
Overhead wires that run through trees to the roofline
Uncovered drain pipes
Plumbing areas below dishwashers
Air spaces in walls around some new houses
Open basement areas especially split or multi level houses
These rats are generally nocturnal, however if commonly seen during the day, it is an indication that the population is huge.