Redback Spider vs Black Widow Spider: 5 Differences

Written by August Croft
Published: March 18, 2022
© Peter Yeeles/Shutterstock.com
Share this post on:
Continue Reading To See This Amazing Video

While these two spiders are technically cousins, there are many differences between a redback spider vs black widow spider. But how can you learn how to tell these two spiders apart, and do you live in an area where both of these spiders also coexist? This may be important for you to know, especially if you have a fear of arachnids!

In this article, we will address everything you need to know about redback spiders and black widow spiders, including what they look like and where they prefer to live. We will also address how venomous they are, as well as their behavior and how likely they are to bite humans. Let’s get started and learn about these two spiders now! 

Comparing Redback Spider vs Black Widow Spider

redback spider vs black widow spider
The redback spider is smaller on average than the black widow spider.

©A-Z-Animals.com

Redback SpiderBlack Widow Spider
SizeLess than half an inch long1 ½ or 2 inches long
AppearanceGlossy black body with red stripe on back; females have trademark hourglass while males are brown in appearance Shiny black in color with a red or orange dot on top of its abdomen; females have trademark red hourglass underneath their abdomen
Location and HabitatAustralia, Asia, and Europe; often found in populated areas and builds webs in any undisturbed area, including wood piles and clutterWorldwide. Found in warmer climates and in well-lit areas. Prefer dryness and hides beneath clutter or outdoor materials so long as they aren’t often disturbed
BehaviorAggressive with its prey and females often eat males; redbacks in Japan hibernate, but others don’tReclusive and highly aggressive if guarding eggs or surprised; will bite more readily than brown widows
Venom LevelExtremely venomous, but less likely to bite humansExtremely venomous and likely to bite humans

Key Differences Between Redback Spider vs Black Widow Spider

redback spider vs black widow spider
While both of these spiders have glossy black bodies, the redback spider features brown males, while all black widow spiders are black.

©iStock.com/maria72

There are many key differences between redback spiders in black widow spiders. The redback spider is smaller on average than the black widow spider. While both of these spiders have glossy black bodies, the redback spider features brown males, while all black widow spiders are black. Finally, the black widow spider is found around the world, while the redback spider is only found in a few locations worldwide.

Let’s talk about these differences in more detail now. 

Redback Spider vs Black Widow Spider: Size

redback spider vs black widow spider
The black widow spider is found around the world, while the redback spider is only found in a few locations worldwide.

©Mark_Kostich/Shutterstock.com

The average black widow spider is far larger than the average redback spider. For example, redback spiders usually grow to less than half an inch in length, while black widow spiders grow anywhere from 1 inch  to 2 inches in length. Either way, this is a spider you don’t want to mess with!

Redback Spider vs Black Widow Spider: Location and Habitat

redback spider vs black widow spider
Both of these spiders have glossy black bodies and red markings on them, but male redback spiders are brown, while male black widow spiders are black or gray.

©iStock.com/KathrynWillmott

The location and habitats of the redback spider and black widow spider vary greatly. This is because the black widow spider is found around the world, while the redback spider is found in Australia, Asia, Europe, and parts of Japan. This also leads to the spiders having different habitat preferences overall. Let’s talk about those now. 

Both black widow spiders and redback spiders build their nests in undisturbed areas that often involve a decent amount of clutter, such as wood piles or attics. However, redback spiders frequently seek out areas near human populations, while black widow spiders prefer remote areas. The average black widow prefers a drier climate compared to a more moist environment where you may find a redback spider. 

Redback Spider vs Black Widow Spider: Appearance

redback spider vs black widow spider
Both redback spiders and black widow spiders have signature hourglasses underneath their abdomens, but redback spiders have red stripes on their back, while black widow spiders have black or orange spots.

©Peter Yeeles/Shutterstock.com

Many people confuse black widow spiders and redback spiders, given that they are cousins with similar appearances. Both of these spiders have glossy black bodies and red markings on them, but male redback spiders are brown, while male black widow spiders are black or gray. However, this is not where their differences end. 

Both redback spiders and black widow spiders have signature hourglasses underneath their abdomens, but redback spiders have red stripes on their back, while black widow spiders have black or orange spots. However, no one would blame you for not being able to tell these two spiders apart, especially because you should simply avoid them if you stumble upon one! 

Redback Spider vs Black Widow Spider: Behavior

redback spider vs black widow spider
For the most part, black widow spiders are regarded as aggressive, especially if they have eggs or a nest nearby, while redback spiders are more shy.

©Sari ONeal/Shutterstock.com

There are some behavioral differences between the redback spider and the black widow spider. For the most part, black widow spiders are regarded as aggressive, especially if they have eggs or a nest nearby, while redback spiders are more shy. However, both spiders will bite if cornered or threatened, though black widow spiders are more likely to pursue an enemy when compared to a redback spider. 

One unique fact about the redback spider is that the redback spiders found in Japan hibernate every winter, which is not the case for any other type of redback spider or black widow. Most spiders seek shelter during the winter months, but this is something completely unique to the redback spiders living in Japan! 

Redback Spider vs Black Widow Spider: Venom Level

Redback Spider vs black widow spider
Both of these spiders are extremely venomous and should be avoided at all costs, but the black widow spider is often regarded as more dangerous than the redback spider.

©whitejellybeans/Shutterstock.com

A final difference between the redback spider and the black widow spider is their venom level. Both of these spiders are extremely venomous and should be avoided at all costs, but the black widow spider is often regarded as more dangerous than the redback spider. This has to do with their behavior more than their venom levels, as a black widow spider is more likely to bite you when compared to a redback spider.


The Featured Image

Close up of Redback Spider
Close up of Redback Spider
© Peter Yeeles/Shutterstock.com

Share this post on:
About the Author

I am a non-binary freelance writer working full-time in Oregon. Graduating Southern Oregon University with a BFA in Theatre and a specialization in creative writing, I have an invested interest in a variety of topics, particularly Pacific Northwest history. When I'm not writing personally or professionally, you can find me camping along the Oregon coast with my high school sweetheart and Chihuahua mix, or in my home kitchen, perfecting recipes in a gleaming cast iron skillet.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.