Animal · United States, Mexico, Dominican Republic
Black widow
Latrodectus mactans — the name this animal has in the language scientists everywhere share.
The black widow is a small, glossy black spider with a red hourglass under her belly, and her venom is stronger drop for drop than a snake's. A bite hurts a great deal but is very rarely deadly, and an antivenom has existed since the nineteen twenties.
Picture credit: Konrad Summers (CC BY-SA 2.0) · Leif902 (CC BY-SA 3.0) · Shenrich91 (CC BY-SA 3.0) · Wikimedia Commons
Where does the black widow live?
Home: Woodpiles, sheds and stone walls in the southern United States.
In the wild it lives in these countries: the United States, Mexico, the Dominican Republic.
The short profile
Fully grown: females 8-13 mm, males 3-6 mm. It weighs about 0 001 kilograms. On the menu: meat.
The story behind it
Only the female is dangerous, and only if she is squeezed or trapped against skin. She is about the size of a fingernail, jet black, with a red hourglass on her underside that warns anything looking up at her. Her web is not a neat wheel but an untidy tangle of threads, spun from silk so strong that it has been tested as a material for its own sake. She hangs upside down in the middle and waits for a beetle or a woodlouse to blunder in. Her venom attacks the nerves, which is why a bite brings cramps and pain rather than a wound, but doctors have had an antivenom since the nineteen twenties. In one American study of more than twenty-three thousand widow bites, not one person died.
Find it on the globe
Black widow is there as a tiny animated figure that breathes and looks around. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.
It sits at its real coordinates, not near them — the same numbers listed in the facts above. Switch off the layer for this kind of place and it disappears again; the buttons for that are down the right-hand edge.
Questions children ask
Is a black widow bite deadly?
Almost never. The bite is painful and can cause cramps and sweating, but in an American study of more than twenty-three thousand bites over nine years, nobody died. Antivenom has been available since the nineteen twenties.
Why is it called a widow?
From the idea that the female eats the male after mating. It does happen, but mostly in glass tanks where the male cannot get away; in the wild he usually walks off alive.
Where do black widows hide?
In dark, dry corners close to the ground: woodpiles, sheds, under garden furniture, in gaps in stone walls. They stay in their webs and only bite when pressed against skin.
Where these numbers come from
Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.
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