Spiders mostly eat insects, although some of the larger species have been known to snack on lizards, birds and even small mammals. Given their abundance and the voraciousness of their appetites, two European biologists recently wondered: If you were to tally up all the food eaten by the world’s entire spider population in a single year, how much would it be? Martin Nyffeler and Klaus Birkhofer published their estimate in the journal the Science of Nature earlier this month, and the number they arrived at is frankly shocking: The world’s spiders consume somewhere between 400 million and 800 million tons of prey in any given year. That means that spiders eat at least as much meat as all 7 billion humans on the planet combined, who the authors note consume about 400 million tons of meat and fish each year.
via https://www.washingtonpost.com/news/wonk/wp/2017/03/28/spiders-could-theoretically-eat-every-human-on-earth-in-one-year/?tid=sm_tw