The secret strategy behind the black widow's bite

The deadly spider is very judicious with its venom

Black widow
(Image credit: (Robin Loznak/ZUMA Press/Corbis))

Venoms generally aren't cheap for animals to produce, in terms of energy. The poisons are often made up of hundreds, even thousands, of components that have to be replenished once a store of venom is used up. Scientists working with venomous snakes have found that replacing depleted venom can increase their daily energy needs from anywhere between 11 percent and 69 percent for several days.

When a weapon comes at a high cost, it makes sense to use it judiciously. "Dry" bites and stings have been reported in various snakes, spiders, and insects, suggesting that they have a choice of whether or not to use venom at all. They also seem to be able to control just how much venom to deploy when they use it. Snakes and spiders have been known to "meter" their venom while hunting, using varying amounts depending on the type of prey and how much it struggles.

Subscribe to The Week

Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.

SUBSCRIBE & SAVE
https://cdn.mos.cms.futurecdn.net/flexiimages/jacafc5zvs1692883516.jpg

Sign up for The Week's Free Newsletters

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

Sign up