Wasps Indoors in Winter: Understanding Seasonal Behavior

Why Wasps Are Inside in Late Fall/Winter

Paper wasps, yellowjackets, and hornets produce reproductive females (future queens) in late summer. These queens leave the nest, mate, and seek sheltered overwintering sites—attics, wall voids, behind trim, ceiling fixtures.

What You're Seeing

• Sluggish, non-aggressive wasps.
• No nest building—just shelter seeking.
• They will not sting unless trapped or crushed.

Management

• Do nothing: They'll leave in spring to start new nests outdoors.
• Vacuum individuals if bothersome.
• Seal entry points after they leave (late spring) to prevent future overwintering.

Why Boric Acid Fails

Boric acid requires insects to walk through it and groom. Overwintering wasps are inactive, not foraging. Dust in voids poses inhalation risk to humans.

Spring Action

In early spring, inspect eaves, shrubs, structures for new nests. Knock down small nests (golf ball size) with a pole at night. For large nests, call a pro.