The black widow, which inhabits southern Canada and all of the United States except Hawaii and Alaska, runs a close second to the tarantula in terms of its ability to strike raw terror into the hearts of people who dread spiders. Yet if we discard reputations, the female black widow really ought to command greater fear and respect than her hairy rival. For starters, she simply looks deadly with her large size (1.5 inches long with legs extended), glossy black body and vivid red marking in the shape of an hourglass. Secondly, she is often found in places that bring her into close contact with humans, such as barns, sheds, woodpiles, outdoor toilets, garages and even homes. And finally, her bite is very poisonous, with venom that is many times more potent than that of many rattlesnakes.

The black widow's bite is nearly painless at first and often goes unnoticed. Typically, the pain begins at the site of the wound, which may swell, then fans out to include the groin, abdomen, legs and large muscle groups throughout the body. Headaches, stiff, severely aching muscles, nausea and difficulty breathing are not uncommon, and the bite victim may even go into shock, though this is rare. A small but significant percentage of humans die of respiratory failure caused by the nervous system toxins contained in the spider's venom. The good news is that such bites are very infrequent, and that most bite victims recover completely after two to three harrowing days of intense pain and discomfort.