Black Widow Spiders: Facts vs. Fears


The female black widow spider is one of the most easily recognizable spiders around, with a shiny black 1-1/2 inch long body and reddish-orange hourglass-like pattern on the underside of her belly (or series of dots). Males are half that size and usually brown or gray with the yellow and red bands with spots on their backs. Black widows get their name from the lore that the females eat the males after mating, leaving them “widowed,” but this seldom happens.

Black widows are typically nocturnal, solitary, and bite only in self-defense. A scientific study found that poking a black widow spider repeatedly with a finger wasn’t enough to get the arachnid to bite. Instead, the prodded black widows in the study often ran away, played dead, or flicked a few strands of silk at their attackers.

They rarely bite humans, but if they do, seek help immediately

If you suspect someone has been bitten by a black widow, stay calm and seek immediate medical care. Bites can be fatal in young children and older people. Symptoms may include trouble breathing, swollen eyes, headache, increased saliva production, nausea and vomiting, excessive sweating, fever, and chills.

These tips can ease symptoms and prevent further infection:

  • Wash the area with soap and water.
  • Apply a cold washcloth or ice pack wrapped in cloth to the area.
  • Take an over-the-counter pain reliever like acetaminophen.
  • If the bite is on your arm or leg, elevate it to prevent swelling.
  • Apply an antibiotic cream or lotion to the bite.

When they do bite, they don’t usually kill

Black widows’ bites are usually venomous only when the spiders feel their lives are in imminent danger. If the threat is less severe, the black widow may deliver what’s known as a dry, or nonvenomous, bite, the researchers found.

In 2013, there were 1,866 black widow bites reported to the American Association of Poison Control Centers, but only 14 of these resulted in severe symptoms. None resulted in death.

They’re awesome!

The tensile strength of a female black widow’s silk is the strongest known substance in nature. It is also the most uniform in size, so much so that it was used for bombsight cross hairs in WWII bombers. An arachnologist once stated that it would be possible to replace the steel cables on the Golden Gate Bridge with black widow silken cables the thickness of a pencil.

Black widows use their silk to build a tangled structure that both traps prey and acts like an early warning system; the slightest vibration brings the spider to investigate immediately. If you find yourself crawling around under your house and feel a strong tug and hear crackling, be on the alert because you just stumbled into a black widow’s web. The web contains silica and tinkles like breaking glass when broken, and the silken blobs about the size of your fingernail hanging in the complex webbing are eggs sacks.

The male does an awesome courtship dance on the female’s web to tell her he’s a male and not a meal!

How to Prevent Contact

  • Keep your home decluttered, dusted, vacuumed, and web free. Ensure all containers are tightly closed.
  • Inspect for cracks and holes in walls, windows, and door frames. Use a flashlight to check dark areas. A good quality silicone caulk can provide durable, flexible, weather-resistant seal.
  • Use dehumidifiers in damp areas of your home, like basements and crawl spaces, as spiders are attracted to moisture.
  • Install yellow light bulbs in outside light fixtures to deter bugs that black widows like to feed upon.
  • Keep your lawn cleared and mowed. Keep bushes, shrubs, and tree branches trimmed back from your house. Keep wood piles, rock piles, and trash piles far from your home.
  • Use a headlamp or flashlight during inspections or cleanups in dark areas, ensuring you can see clearly to avoid unexpected encounters.
  • Before handling areas where spiders might be present, dress in long-sleeve shirts tucked into long pants (tucked into long socks), and gloves. Never attempt to clear webs with your bare hands.

Ways to Remove Spiders

  • Capture and release spiders using a clear jar or glass and a piece of stiff paper or cardboard. Place the jar over the spider and against a flat surface, then slide the paper over the opening. Secure the lid and release the spider far away from residential areas.
  • Place sticky traps specifically for catching spiders along edges (e.g. where a wall meets the floor), corners, behind furniture, in closets, under appliances, in basements, and in garages.
  • Vacuum the spiders, webs, and egg sacs. Empty the vacuum bag and put waste remnants in a plastic bag immediately, seal it, and dispose in an outdoor garbage cart.
  • Use a spray repellent such as the nontoxic, effective Web-Away Spider Eliminator, available at com.

Quality living for all neighbors