House spiders in the Greater Toronto Area build webs in quiet corners: basements, window wells, garages and ceiling edges. They do not damage wood or wiring. A sudden number of spiders usually means the basement has the insects they eat, often alongside damp conditions that also suit silverfish and centipedes.
Often, yes. Spiders stay where there is food. A basement full of webs usually also has the smaller insects those spiders are catching, and often a moisture issue.
Quiet, undisturbed corners: the basement, window wells, the garage, and the edge where the ceiling meets the wall. They are less common in busy, bright kitchens.
