Pest Problems

False Widow Vs. Black Widow Spider – How To Differentiate Them

Spiders – not the most loved types of creatures on this planet. And how could they be? These 8-leged creepy-crawlies are one of Mother Nature’s not so many, but definitely most cruel jokes. That said, among the 40,000+ spider species, there are some that are far more dangerous than others, the most popular representative being the black widow spider.  

Now, did you know that black widows have not-as-poisonous doppelgangers, called false widow spiders? Yup, and truth be told – if you take a closer look, they actually don’t look that much alike. In this article, we are going to tell you how exactly to differentiate the two spider types.

Table of Contents:

So, if you:

  • have suspicions that you have a black widow spider in your house;
  • want to know how to tell apart a false widow from a black widow spider;
  • are just curious about spiders and stumbled upon on this article.

Fantastic Services is here to tell you everything you need to know about the difference between the two spider species.

But first… 

Why is it important to know the difference between a false widow and a black widow spider?

The answer is very simple – it’s a matter of safety. Imagine that one day, while cleaning around your house, you see a spider crawling up your leg. You decide to save it because nice people don’t kill defenceless spiders, and BAM! – THE SPIDER BITES YOU! 

Now what? The bite mark starts swelling, becomes itchy, and you have no idea what attacked you, and more importantly – how to act. 

What if a black widow bit you, and you didn’t know? That’s why it’s so important to learn about the difference between the spider specie and its doppelganger.

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Black Widow Spider (Latrodectus mactans)


When you imagine a black widow spider, you are basically thinking about the female, because that’s the black, shiny one, with the red hourglass on its belly or back. A male black widow is a lot less “intimidating” in colour – they also have a red marking, but it’s not as prominent as the female’s. 

In terms of shape and size, the lady spider is 35-40 mm (including the leg length) and has a round body, while the male one is half the size and “thinner”. Needless to say, both female and male black widow spiders are terrifying and we hope that you never spot one. 

Habitat & Diet

Black widow spiders like to be close to the ground and enjoy more dark and secluded areas, which makes them even creepier, to be honest. Typically, the 8-legged crawlies can be found building their nest inside an abandoned mouse hole, in woodpiles, or the bottom part of a shrub.

That’s for the outdoors. Indoors, black widows can be found netting a home, again, around undisturbed areas, such as under that forgotten sofa you have in the basement. 

And as for their feeding preferences, black widow spiders like to eat crawlies such as woodlice, diplopods, chilopods and other arachnids.


A black widow spider bite is something very serious. Their venom is extremely potent – up to 15 times more concentrated than that of a rattlesnake! That said, a female black widow is far more dangerous when it comes to biting than a male one.

Why? Well, remember how we said that lady widow spiders are bigger than boy spiders? Well, the bigger size of the female black widow also means that she carries a bigger amount of venom in her system, which makes her bite capable of inflicting more damage to your system than that of a male one. 

Now, you may be wondering what happens when a black widow spider bites you? It’s not a very pleasurable experience, we’ll give you that. The symptoms of a spider bite typically last between 2 to 3 days and can including the following:

  • Muscle pain;
  • Chest pain;
  • Swelling;
  • Nausea;
  • Breathing difficulty;
  • Restlessness;
  • Anxiety;

If you get bitten by a black widow spider, make an appointment with your doctor ASAP.

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False Widow Spider (Steatoda nobilis)


False widow spiders look very similar to black widow ones (hence the name). Again, the female representatives are larger than the male ones – a lady false widow can reach up to 15 mm in size, while the male one can grow only to 10 mm. In terms of shape, false widow spiders have round, bulbous bodies, the male’s one being a tiny bit slimmer than the female’s.

The main difference between a false widow spider and a black one is the colouring – unlike its very venomous almost-twin, the false widow is brown in colour.

Habitat & Diet

False widows like to live close to nature, so you can find one sleeping inside a tree’s bark or under a rock. However, this doesn’t mean that you won’t see a false widow near your home or inside of it – this type of spider also enjoys napping in walls or on fences.

False widows have very poor eyesight and aren’t very aggressive. If you get attacked by one, you most probably just scared the poor creature and it tried to defend itself. 

In terms of diet, false widow spiders like to munch on crawling insects, such as other types of spiders, including on black widow ones. Talking about Animal Planet worthy stuff…


If by any chance, a false widow spider decided to bite you, it will be a male one and you won’t feel it immediately. The venom will need about 20 minutes to do its work for you to start experiencing symptoms. The general signs of a false widow bite include a local burning sensation, pain, swelling and wealing

A false widow bite is not as dangerous as a black widow one, due to the fact that the venom is not as strong. The effects of the bite are also shorter – all of the symptoms will be gone after 12 to 24 hours. 

However, if you start developing an allergic reaction or an infection, make sure to visit your doctor for proper treatment.

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Do you need professional pest control assistance?

Has a false widow family decided to make a home out of your property and you just can’t stand the sight of spiders randomly popping up? Then why not call Fantastic Services?

We offer professional spider control, along with a range of other pest control services, suitable for any kind of situation, including a false widow invasion. Our methods are tried and tested and the professionals we work with – experienced, qualified and certified to deal with nasty spiders. Book an appointment today and we’ll send all 8-legged intruders packing!

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  • There are two main visual differences between a false widow and a black widow: size and colour. Black widow spiders are far bigger and black in colour (duh), while its doppelganger is brown and a lot smaller. 
  • Keep your house spider-free by making sure to regularly vacuum cobwebs and to keep an insecticidal spray close by. 
  • If you get bitten by a black widow spider, visit your doctor as soon as possible.


Did you find our article helpful? Make sure to leave your thoughts and experiences in the section below!

Image source: Polly Ivanova Illustration

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