Animal IQ

Spiders Kill A Mind-Boggling Number Of Insects, So Maybe You Shouldn't Squash Them

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When you come upon a spider in your house, what do you do? Some people choose to squash it so they won't have to share space with a creepy crawly critter. Others might leave it alone because they know it'll most likely eat insects, thereby cutting down the overall population of creepy crawly critters in their home. New research is showing that those in the latter camp have it right: the amount of insects spiders eat every year is so astronomical that it rivals our own human-sized diets.

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Eight-Legged Gluttons

For a 2017 study published in The Science of Nature, European researchers Martin Nyffeler and Klaus Birkhofer combed through the data of 65 previous studies to calculate how much prey the world's spiders kill every year. They calculated that altogether, there are about 25 million metric tons of spiders on earth, mostly in forests, grasslands, and shrublands. Then, they combined the amount most spiders need to eat to live with the prey capture rates that field researchers had observed and came to their final tally: spiders kill an estimated 400 to 800 million tons of prey annually.

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Move Over, Humans

The press release puts this massive number into a context regular people can understand: together, all humans eat an estimated 400 million tons of meat and fish every year. Compare the size of an average human's dinner plate to the size of your average house spider, and you begin to understand the quantities we're talking about.

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"Whales feed on 280 to 500 million tons of seafood," the press release continues, "while the world's total seabird population eats an estimated 70 million tons of fish and other seafood." These are all animals that are much, much bigger than our eight-legged friends. So the next time you spot a spider and are tempted to grab a tennis shoe, stop. Think about all the other critters that will meet their end thanks to your intended victim, and feel comforted that you'll have that many fewer bugs in your house.

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Watch And Learn: Our Favorite Content About Spiders

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