Although we see a lot of wildlife in BC, not every species is native to the province. Many were brought here from other parts of the world, either on purpose or by accident. Some of these introduced animals are also invasive and cause harm to the environment, the economy or are just plain troublesome to live with.
Both the black rat or ship rat (Rattus rattus) and the Norway rat or brown rat (Rattus norvegicus) arrived in BC by accident, most likely as stowaways on cargo ships. The Norway rat tends to outcompete the black rat in temperate zones but both species can carry diseases and cause general problems if present in urban settings.
Rats can be very destructive, contaminating food stores, chewing wiring and decimating ground nesting birds, especially in island ecosystems where predators are often rare. “I’ve seen rats eat eggs and kill fledging chicks of ground nesting sea birds” said Sue Davies of the Columbia Shuswap Invasive Species Society, “they can totally decimate bird populations that have evolved in places without naturally occurring ground predators,” she said.
Rats tend to go where there is available food, water and shelter. The best way to exclude rats from your property is to ensure all potential rat food (including birdfeed and animal food) is stored in rat proof containers. Clean bird feeders daily and only add a small amount of bird feed at a time. Smelly compost may also attract rats, see revelstokebearaware.org/be-bear-aware/composting for information on keeping your compost odour free and less attractive to rats.
Fixing water leaks and removing open water bowls can reduce the chances of rats taking up residence at your property, as can sealing or barricading easy access points to all indoor locations. Fall is the season when many rodents begin nesting for the winter; take the above steps to ensure that you are not inviting invasive rats into your home! See the fact sheet on our website (columbiashuswapinvasives.org/about-csiss/csiss-resources/) for more in-depth information about dealing with rat infestations.
Invasive species are of concern across Canada, and humans can play a large role in preventing their spread.
Invasive Rat Factsheet– California