Are there more rats in Vancouver than ever before, or are people just more aware of them now? There has been very little research on rat populations in cities, and the Vancouver Rat Project aims to change that. Veterinary pathologist Chelsea Himsworth is leading a team that captures, analyzes, and tags rats to see where they live, how they behave, in what diseases they may be carrying. One thing they know is that rats thrive in urban areas because rats always thrive where the natural world has been disrupted.
Which brings into question the constant human quest to disrupt rats and their habitats. As much as rats thrive in disrupted environments, Byers says, they’ve managed to create very stable colonies within them. Rats live in tight-knit family groups that are confined to single city blocks, and which rarely interact. The Rat Project hypothesized that when a rat is ousted from its family by pest control, its family might flee its single-block territory, spreading diseases that are usually effectively quarantined to that family. In other words, the current pest control approach of killing one rat per concerned homeowner call could be backfiring, and spreading disease rather than preventing it.