In British Columbia, there are more than 900 species of spider! Almost every spider has venom that it uses to subdue its prey, but there is only one species of spider in British Columbia that’s venom can be harmful to humans.



– Most dangerous spider in British Columbia
– Symptoms of a Western Black Widow Spider bite
– Why do spiders bite?
– What to do about spiders in my home?


Most dangerous spider in British Columbia

There is only one species of spider in British Columbia that can be dangerous to you, which is the black widow spider. The species found in mainland British Columbia and on Vancouver Island is the Western Black Widow spider.

black widow spider

Female black widows are the real venomous champions, delivering stronger bites compared to males. They’re shiny, coal-black spiders with a distinct marking on their underside, often resembling an hourglass. These fascinating spiders are usually around 3.8 cm (1.5 in.) long but can be smaller.

When it comes to their diet, these spiders are not picky eaters. They primarily feast on a variety of insects, but they also occasionally indulge in other arachnids. Their hunting strategy involves patiently waiting in their intricate webs until an unsuspecting prey becomes entangled.

If you’re wondering where you might come across these intriguing spiders, keep an eye out for their low-lying webs. They can sometimes be found in garages, around barbecue grills, near swimming pools, and even in wood piles. These spiders tend to favour rural and suburban areas and are most active between the months of April and October. It’s important to note that black widows typically only bite in self-defence and try to avoid humans and their homes when possible.


Symptoms of a western black widow spider bite

While black widow spider bites are concerning for everyone, they are most serious when they affect babies, children, or older adults. However, no matter what age it’s important to seek medical attention promptly if a bite occurs.

Common Black Widow Spider Bite Symptoms:

When it comes to black widow spider bites, the majority of cases involve the following symptoms:

  • Minimal to sharp pain followed by swelling and redness at the bite site.
  • Presence of one or two small fang marks resembling tiny red spots.

Severe Symptoms:

In some instances, more severe symptoms may manifest within 30 to 60 minutes after the bite. These can include:

  • Muscle cramps and spasms originating near the bite and gradually intensifying, spreading throughout the body and lasting for 6 to 12 hours.
  • Seizures.
  • Chills, fever, nausea, or vomiting.
  • Profuse sweating.
  • Intense belly, back, or chest pain.
  • Headaches.
  • Restlessness, stupor, or shock.
  • Markedly high blood pressure.

If you experience any of these severe symptoms after a black widow spider bite, seek immediate medical attention.

Why do spiders bite?

If you have a fear of spiders, rest assured that they aren’t out to get us. Contrary to their portrayal in media, spiders don’t view humans as food or enemies. Their first response to encounters with us is typically to run, hide, or play dead. Only as a last resort for self-defence, will they bite.

Spiders are selective about using their venom because it is crucial for their survival and once the venom is expended, it takes time for them to replenish it. Fascinatingly, studies have shown that even when provoked or harassed, spiders like black widows refrain from biting. Only when physically squeezed or pressed do they resort to biting and injecting venom.

Remember, spiders rely on their venom to immobilize the insects they feed on, such as flies and mosquitoes. Wasting venom on humans could lead to starvation before their bodies can produce more.

So, while it’s natural to have concerns about spider bites, understanding their behaviour and priorities can help alleviate unnecessary fears.


What to do about spiders in my home?

During this time of year, you might encounter spiders walking across your living room or finding their way into your bathtub. Don’t worry! The most common species you’ll find include garden cross orb weavers, giant house spiders, and hobo spiders – none of which pose any risk to humans. So, if you spot these visitors, appreciate their role in nature’s cycle and remember they won’t cause any harm. However, if you are noticing a large number of spiders in your home or a dangerous spider such as the black widow, it’s a good idea to call on pest control professionals to remedy the situation.


Did you know? The brown recluse spider is never found in British Columbia, but there are stories every year of people saying they’ve seen one or killed one. In fact, it only lives in the southeastern US.

Brown recluse spider

Old Island Pest Control offers pest management and exterminator services for both residential and commercial properties. We have local pest control experts at locations across Vancouver Island, including Duncan, Nanaimo, Parksville & Qualicum, Courtenay, Victoria and Campbell River. Call us today to learn how we can help.