Black widow spiders are well known for their shiny black bodies and the red hourglass marking on the underside of the abdomen. They are one of the most recognizable spiders in North America and a common concern for homeowners throughout Idaho. While bites are rare, the venom of a female black widow can cause significant pain and requires prompt medical attention.
Many homeowners wonder what happens to black widows during the colder months. Understanding their seasonal behavior helps with prevention and year-round control.
Do Black Widows Hibernate?
Black widows do not truly hibernate. Instead, they slow their activity as temperatures drop. During cold weather, they typically:
- Remain hidden inside webs or protected shelters
- Move very little during daytime hours
- Conserve energy during prolonged cold periods
- Seek warmer locations such as garages, crawlspaces, sheds, and foundations
They may still become active on milder winter days, which means Idaho homeowners can encounter black widows year-round. When temperatures fall below about 50 degrees, movement decreases significantly, but the spiders do not die. As soon as conditions warm, activity resumes.
This is why winter is still an important time for monitoring and prevention around Treasure Valley homes.
Types of Widow Spiders
Widow spiders belong to the genus Latrodectus. While more than thirty species exist worldwide, only a few are commonly encountered in the United States.
- Southern black widow (Latrodectus mactans)
- Northern black widow (Latrodectus variolus)
- Western black widow (Latrodectus hesperus)
- Brown widow (Latrodectus geometricus)
In Idaho, homeowners most commonly encounter the Western black widow. Male widows are much smaller and rarely bite. Females are larger, more defensive, and responsible for medically significant bites.
Where Black Widows Live
Black widows prefer dark, undisturbed areas where insects are plentiful. Common hiding locations include:
- Garages and storage rooms
- Crawlspaces and basements
- Woodpiles and debris piles
- Eaves, corners, and outdoor structures
- Unused shoes, gloves, and stored boxes
- Cracks and gaps around foundations or steps
They build irregular, messy webs close to the ground and typically remain hidden during the day. In winter, these protected locations provide warmth and stability.
Are Black Widows Active Inside Homes During Winter?
Yes. When outdoor temperatures drop, black widows may move into homes, garages, and outbuildings seeking warmth. Indoors, they can remain active throughout the winter.
Common signs include:
- Irregular webs near floor level or corners
- Egg sacs attached to webs or hidden surfaces
- Spiders found in cluttered or undisturbed areas
Because activity slows during colder months, infestations often go unnoticed until spring.
How to Reduce Black Widow Activity Around Your Home
Prevention is the most effective long-term strategy. Homeowners can reduce black widow activity by:
- Sealing cracks and gaps along foundations, doors, and windows
- Reducing clutter in garages, basements, and storage areas
- Keeping firewood stacked away from the structure
- Removing outdoor debris and wood piles
- Wearing gloves when handling stored items or working in crawlspaces
- Limiting exterior lighting that attracts insect prey
These steps make your home less appealing as a winter shelter for spiders.
Related Spider & Pest Resources
Professional Control for Black Widow Spiders
Because black widows prefer hidden locations and can produce multiple egg sacs, professional treatment is often the most reliable solution.
A Pestcom Pest Management technician can:
- Identify active hiding and nesting areas
- Remove webs and egg sacs
- Apply targeted treatments to cracks and low-visibility zones
- Create a long-term prevention plan tailored to Idaho homes
Homeowners across Boise, Meridian, Nampa, and the surrounding Treasure Valley rely on winter and spring spider control to prevent seasonal population surges.
For safe and effective black widow spider control, contact Pestcom Pest Management today.