Black Widows: What You Need to Know

One of the few venomous spiders in North America, the black widow, is very common in California and Nevada. Identifying the black widow is fairly easy to do; identifying how and why they invaded your home or business is another matter.

In today’s post we will review the need-to-know facts about black widows and the dangers they present.

Black Widow Spider Facts

The black widow is a glossy, jet- black arachnid with eight thick, glossy legs. Her most important identifier is the red mark on her belly shaped like an hour glass. There are “false” black widows which look very similar in appearance, with dark brown abdomens and no red hour glass marking. On occasion a true black widow is spotted that has a brownish hue to the abdomen, which simply means she is very well fed.

Behavior and Lifestyle:
The black widow is known to thrive in hot, desert conditions but can also survive in mountainous regions. They look for easy “retreats” with good insect traffic so they can hide from predators when not hunting. Outside the home this could be in rock walls, drains, vents, clutter, wood piles, or trash cans. Black widows often make their way into the home in storage boxes brought in from garages or firewood brought in from the outside. Black widow webs are often spotted in these areas and should be a good indicator of activity- the webs are used to lay eggs and catch prey.

Wood piles are common hiding places for black widows and other spiders

Bite Symptoms:
While not all black widows bites result in severe reactions, an untreated bite has the potential to be fatal and should be examined by a physician right away. Symptoms of a bite range from mild redness and swelling to severe pain and nausea. Those most susceptible to spider bites are children, the elderly, or those with compromised immune systems due to illness. Here are a few common symptoms to look out for if you think you may have a black widow bite:

• Fever, sweating
• Headache
• Abdominal pain
• Mild to severe pain and/or throbbing 
• Joint pain or stiffness
• Chills or other flu-like symptoms
• Rash

Depending on the person bit and the amount of venom released, the appearances of bites vary so relying on symptoms will be helpful if you did not see what bit you.

A black widow and her nest- recently found at an Advanced IPM customer’s home

Prevention and Control:
The key to controlling a black widow population in your home or business is figuring out what attracts them there in the first place. If black widows are commonly seen inside, there is something bringing them in regularly or making the indoors especially habitable for them. Cleaning up clutter and maintaining sanitary conditions inside and out is a good start. If spiders are continually spotted indoors, there may be an entry point you are unaware of or too many other insects (spider food) indoors.

Sometimes the cause or entry point of spiders is not so easy to find. The professionals at Advanced IPM are specially trained to determine the cause and appropriate solutions for such infestations. Submit a request today for your no-charge inspection with one of our friendly pest control technicians!