Does it feel like the mosquitoes are worse this year? Do they bite more frequently? Are they lingering much longer than usual? None of that is good. But it's not the worse-case scenario. In Canada, at least for now, mosquitoes are a bloody nuisance. Over the scope of human history around the world, however, they're merciless spreaders of fatal diseases. And as Canada warms, those mosquitoes come closer. So yeah, it's not exactly hyperbole. If there's one creature most likely to devastate a human population, it's that little jerk buzzing around your bedroom. GUEST: Dr. David Fisman, epidemiologist, Dalla Lana School of Public Health