Why Are Certain Female Killers Called Black Widows? It All Goes Back To A Popular Myth

Any true crime fan will tell you the most famous murderers are mostly all men. In fact, about 90 percent of homicides worldwide were committed by men, per a 2019 edition of the Global Study on Homicide from the United Nations.

But that doesn't mean women never kill. One kind of female murderer has become so infamous its even sparked its own nickname: Black Widow.

As seen in the new Oxygen series "Black Widow Murders," premiering Sunday, September 25 at 7/6c, a black widow is a woman who kills multiple people, usually partners, for financial reasons. The method of murder is irrelevant to the name — she may choose to use poison, stage an accident, get a gun, hire someone, or what have you — but the motive of material gain is what makes her a Black Widow.

But why exactly are women who kill their lovers over money they called that?

Well, the name arises from a specific kind of spider: the Black Widow. Black widows are part of the Latrodectus genus, and are found in temperate places all around the world, including North America (although you'll find them more often in the southern and western states of America), according to LiveScience. They're the most venomous spiders found in the U.S., so people are naturally wary of them (although people rarely die from their bite).

However, it's not their level of poison that has them compared to deadly females. Instead, it's because of the widely-circulated myth that female spiders eat their male counterparts after sex. While this does sometimes happen, it's not the usual occurrence, according to the Burke Museum of Natural History and Culture in Seattle, Washington. 

Scientists did witness females devour their mates after sex while researching the creatures in a lab, but as The Smithsonian noted, in those circumstances it's a lot harder for male spiders to get away from the female black widows, which are much larger than them. Out in the wild, it's less of a problem, scientists theorize.

Still, that myth of black widow spiders as sexual cannibals persists to this day, and directly inspired the moniker for women who decide to murder their lovers. "Black Widow" killings are even mentioned in the FBI's breakdown of serial murder.

To learn more about these kind of murderers, turn in to "Black Widow Murders," when it premieres Sunday, September 25 at 7/6c on Oxygen.