Research Shows Some Male Spiders Bite And Bind Female Spiders Before Mating

spider portrait with 7x magnification and full depth of view

By Mayukh Saha / Truth Theory

We are all aware of the black widows and their gruesome ways of eating the male spiders after mating. It’s not just black widows; this is a practice common to many other species of spiders as well. But did you know that some male spiders have evolved to survive this mating practice? 

Traditionally, researchers have observed that many male spiders spend hours wooing their female counterparts. However, recent studies have brought forth some species where the males just bite and bind the females before mating. This out-of-the-ordinary animal behavior has been noticed in thanatus fabricii. 

Evolved Courting Behavior In Some Spiders 

In recent research, scientists studied thanatus fabricii’s adaptive venoms. They also looked at their general behavior. During the course of the research, the scientists saw that the males not only tied the females but also bit them. If you are wondering at the strange nature of this behavior, stick with us a little longer. It will all become clear soon. Like everything, this behavioral change also has a reason. 

The researchers also observed that the female spiders became immobile after the bite. This is when the male spiders began the mating process. The larger the female spiders were, the longer the male spiders would bite them. Understandably so, as the larger females needed bigger doses of venom to make them immobile. Additionally, the researchers also saw that if the females missed a leg or two, the males bit less. 

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They also saw that male spiders with longer legs could affect the females more with their venom. And because the males tied their females with silk, they got a longer duration of time to perform. 

Did Thanatus Fabricii Males Adapt To The Dangers Of Being Eaten By Their Mate After Copulation?

The researchers observed that the female spiders were left negatively affected after the entire process. They saw that they couldn’t catch their prey as easily as they could before. It seemed that their state of immobility lasted even after the male thanatus fabricii left. 


After the study, the researchers state that thanatus fabricii mates coercively. The males have larger glands for venom. However, the venom composition is practically the same between the males and the females. It appears that the male thanatus fabricii spiders adapted this coercive mating technique through venom adaptation. In other words, the male spiders of this species evolved to avoid getting eaten at the end of their mating session. 

It should also be noted that the male thanatus fabricii is better at coercive mating than foraging food. It looks like they prefer biological multiplication more than the need to eat.

Image Featured: Acon Cheng

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