# Winter Spiders in Ontario — Spider Squad

## What Happens to Spiders in Winter

Ontario winters eliminate many spider populations, but not all. Different species use different overwintering strategies.

**Egg sacs:** Most orb weavers and many other outdoor spiders die with the first hard frost. Before dying, females deposit eggs in silk egg sacs in protected exterior locations — under bark, in wood piles, under deck boards, inside soffit voids. These egg sacs are cold-resistant and survive Ontario winters. Spiders hatch in spring.

**Overwintering adults:** Some species overwinter as adults in a dormant or semi-dormant state in protected exterior zones. These include certain funnel web spiders and some hunting spiders.

**Indoor species:** House spiders, cellar spiders, and yellow sac spiders that are living in heated interior spaces continue to be active year-round. They're just less visible in winter because we're less observant, not because they're gone.

## What You're Seeing in Winter

Spiders active in a heated home during January or February are almost certainly house spiders or cellar spiders — species adapted to living indoors year-round. They were likely present in summer and fall but less noticed.

Occasionally a wolf spider or hunting spider that moved indoors in fall will be encountered in winter, but these typically decline as their insect food supply inside the home decreases.

## The Egg Sac Risk

The biggest winter-related spider concern is egg sacs on exterior structures. A single egg sac from a house spider can contain 100 to 400 eggs. Egg sacs from orb weavers and other species deposited on your eaves, under deck boards, or in soffit voids will hatch in spring and produce the next generation of spiders on your property.

**Web cleanout** as part of a fall Spider Squad treatment removes visible egg sacs from exterior surfaces, reducing the spring population you'll be dealing with.

**Winter inspection:** Walking your exterior in late winter (February to March) before snow melts can help identify egg sac concentrations. Common locations: under eave overhangs, inside soffit vent covers, in gaps around window frames, under deck boards near the structure, and in any sheltered corner.

## Treatment Timing for Winter Egg Sac Concerns

Professional treatment does not affect egg sacs directly — the eggs inside are protected by the silk. The most effective approach for egg sac management is physical removal (web cleanout) before spring hatching.

A spring treatment applied in April to May intercepts newly hatched spiderlings and emerging overwintered adults at the point when the new generation is most vulnerable.

For year-round coverage, the annual maintenance plan handles both the spring and fall treatment windows automatically.

To book: call 905-935-7498 or request a quote at spidersquad.ca.