9 of the World’s Deadliest Spiders: Quick Facts

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A medically significant arachnid

Brazilian wandering spider

Illustration of a black widow spider (Latrodectus mactans) shown from above, with a close-up ventral view highlighting the red hourglass marking on its underside. A scale bar compares its size to 3 centimeters and 1 inch.

Brown widow spider

Illustration of a red widow spider (Latrodectus bishopi) showing its reddish legs and cephalothorax, with a black abdomen marked by red and white spots. A scale beside the spider indicates its size is about 3 centimeters or 1 inch.

A Redback spider (Latrodectus hasselti) with a shiny black body and distinctive red stripe on its rounded abdomen stands on a light tan surface.

Sydney funnel-web spider (Atrax robusta) with a shiny black body and thick legs, shown on rough brown bark in its natural habitat.

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