Spiders

• WHAT YOU SEE

A web across the porch light, another in the corner of the garage, one rebuilt overnight in the same doorway you cleared yesterday. Most of what you notice is the web, not the spider, and the web is usually up high, on the eaves, the fixtures, or the window frames. Indoors it's more often a single spider in a basement corner or behind a stored box than a web in the middle of a room. They're not chewing anything or nesting in a colony, so one spider rarely means a bigger problem behind it.

• WHAT WE SEE

Spiders build where the flying insects are, which usually means near a light source: the porch fixture, a window that stays lit at night, a gutter corner that collects gnats. Warm white and yellow bulbs draw far fewer insects than cool white ones, so the light itself is often part of the fix. Indoors, spiders show up where there's something to eat and somewhere quiet to wait, which in a Midwest house is usually a damp basement corner, a garage shelf, or behind furniture that doesn't move. A lot of what looks like a spider infestation is really one or two spiders using the same undisturbed corner for weeks.

• HOW WE FIX IT

The eaves, gutters, fixtures and window frames get de-webbed and treated on every quarterly visit, not just when you call. We treat where the webs anchor, not just where they're visible, so they're slower to come back. Indoors we treat the basement, garage and other quiet corners on request, and it's free between visits if something new shows up. Sealing gaps around trim and utility lines cuts down on both the spiders and the insects they're hunting.

• WHEN THEY SHOW UP

Spiders are active outside from spring through fall and move toward shelter as it cools, which is when you're most likely to find one indoors. Web-building picks up in late summer, when the flying insects it depends on peak around porch lights and gutters. Indoors, a damp basement or an undisturbed garage corner can host a spider year round, cold weather or not. The eaves, garage, bedroom and living room are the rooms we check most; a web outside a window is usually connected to one of them.

• WHAT THE PROS KNOW

Webs on the eaves are a sign, not just a mess: spiders build where flying insects are drawn to your lights. Warm-colored bulbs draw fewer of them.