All spiders are venomous, as that is how they paralyze and capture their prey. However, few disperse enough venom or have strong enough venom enough to affect humans.
That said, there are three spiders that are venomous to humans that are commonly found in some parts of the U.S. These include
- Black widow - found throughout North America, but are most common in the southern and western areas
- Brown recluse - most commonly found in the Midwestern and southern states
- Hobo spiders – found throughout the Pacific Northwest.
These spiders are primarily found outdoors, and can be dangerous to homeowners working outdoors doing chores such as landscaping, gardening, roofing, or other construction work if a person were to inadvertently disturb or contact them. They may also come indoors in areas where they are prevalent.
Although these spiders definitely can be dangerous, they are generally not aggressive and will only bit if contacted, disturbed, or trapped.
Symptoms of a Spider Bite
According to the Center for Disease Control and Prevention (CDC), the symptoms of a spider bites can vary. Some can be quite minor, while others can be very severe, even resulting in death in rare cases. The center lists possible symptoms as:
- Itching or rash
- Pain radiating from the site of the bite
- Muscle pain or cramping
- Reddish to purplish color or blistering
- Increased sweating
- Difficulty breathing
- Nausea and vomiting
- Anxiety or restlessness
- High blood pressure
If you think you, or another person, has been bitten by a spider and any of these symptoms are experienced, you are advised to seek medical attention immediately. Additionally, wash the area with soap and water, then elevate the bitten area and apply an ice pack to reduce swelling.
If possible, identify the suspected spider, as that will make any needed medical treatment more applicable.
Prevent Spider Invasion and Bites
As with so many pests, the best defense against spiders and possible bites is preventing their presence and contact with them. As advised by CDC and other experts:
- Inside the home, reduce clutter and piles to reduce areas in which spiders may seek shelter.
- Dust regularly, particularly into corners and ceiling/wall junctures, and under beds and furniture where spiders spin webs.
- Use plastic instead of cardboard storage boxing whenever possible. Spiders are much more attracted to cardboard.
- When stacking materials, minimize the empty spaces between each to reduce spider (and other pest) harborage areas.
- Outdoors, remove and reduce debris and rubble from around the home, and trim or eliminate tall grasses and other rambling foliage.
- If clothing, shoes, towels, or equipment have been stored in a garage, shed, basement or any area that spiders may be seeking harborage, inspect of shake them out before putting them on or using them.
- When apparel and equipment is stored outdoors, it is advisable to place them in plastic bags, when practical, or use equipment covers on larger items.
- If working in areas where spiders may harbor, such as around or handling stacked or undisturbed piles of materials, wear protective clothing such as a long-sleeved shirt and long pants, hat, gloves, and boots.
- Ensure that you update your tetanus shot every 10 years, as spider bites can become infected with tetanus spores.
Control of Spiders
Spiders can be controlled through a variety of methods, with an integration of pest management techniques as the most effective. Techniques include exclusion, sanitation, chemical and non-chemical controls indoor and/or out. Read more about each of these at Get Rid of Spiders in the Home.