Black Widow Spider

The Black Widow Spider

Latrodectus Theridiidae is the scientific name of one of the most dangerous species of spiders which are commonly known as the Black Widow spider. These black colored spiders are generally found in America and Canada and their bites are highly toxic.


The length of adult black widows ranges between 1/8 to 1.5 inches. Most black widows have a very shiny coal black colored body with red marks on their spherical abdomen; sometimes they have a brown-colored body bearing orange colored markings. The markings are mostly hourglass-shaped. Males are smaller in size as compared to females, almost half in size and usually are brown or grey colored.

Black Widow Spider Behavior:

Black widow spider behavior

Black widow spider behavior

Black Widow spiders are not aggressive, but when disturbed or feel threatened they bite their victim right away.

These spiders have been associated with the belief that they eat their male partners after mating. This is the reason they are given the name “Widow”. However, recent studies have shown that not ALL black widows have this habit after mating and the species that do don’t do it all the time.

They are reclusive in nature, therefore they build webs in dark, isolated and hard to reach places like under ledges, in boxes, among firewood, in the dark corners and edges of garage or backyard. They spin structure-less, haphazard webs. Black Widows opt places for webbing which are secured and have least chances to be disturbed.

Signs of Black Widow Spiders:

Messy webs within a foot of the ground hint towards the presence of black widows. And if you come across any spider, look for hourglass-shaped marking on its abdomen to identify it as a black widow.

Black widow bites are extremely painful followed by symptoms like severe muscle pain, abdominal pain, nausea, vomiting and breathing difficulties. Witnessing these symptoms demand emergency medical treatment, otherwise, they can result in lethal convulsions.


It is also important to know the reasons why these spiders invade our home.

The very 1st and common mean to enter your home is through pipes, windows or such kind of sneaky areas. Another way they can sneak into your home is through cracks in walls.

Usually, these Spiders live undercover, like inside pallet of boxes, under clutter, etc. So if your house has a storeroom which is not been constantly visited, then you might not be surprised by the presence of Black Widow Spiders there.


The threats attached with Black Widow Spiders force us to take immediate remedial measures as soon as we spot them. Following ways will help you in controlling and eradicating these dangerous creatures.

Insecticidal dust and sprays:

Black Widow spiders are nocturnal, so locate their webs during daytime in the dark, secluded places. Once you locate their hideout, sprinkle or spray the anti-spider insecticide dust or liquid directly on their webs and surroundings. These will kill the spiders upon contact.


For indoor webs, you can use a vacuum cleaner; it will instantly suck the spiders even from the nooks and corners.

Remove egg sacs:

Look for any hanging egg sacs in the webs and either generously apply insecticide on them or vacuum them off. They contain hundreds of eggs and if left there, they’ll cause black widow infestation.

Don’t forget to wear protective gear, gloves and boots to avoid spider bites, and if you aren’t sure, it’s better to call a professional.

Preventive measures:

Make your house unappealing for Black Widows by regularly cleaning it and reducing clutter both indoors and outdoors. Seal the cracks in walls and caulk the gaps in windows and doors to eliminate their possible entry points.

Black Widow Spider Facts

  • Black widows are nocturnal spiders and hunt their prey at night.
  • Only female black widows’ bites are lethal.
  • Venom of female black widows is 15 times more toxic than the venom of rattlesnake.
  • They are territorial spiders and build webs a foot apart from each other.

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