It may sound like something from a horror film, but two scientists writing in the Journal of Science and Nature have revealed that the world’s spiders could consume every person on earth in less than a year! Martin Nffeler and Klaus Birkhofer used existing research and some scientific estimates to arrive at their slightly concerning conclusion!
We are quite literally surrounded by spiders, as shown by a recent survey of homes in North Carolina, which found that 100% of them contained spiders, including 68% of bathrooms and over 75% of bedrooms.
Taking things further than North Carolina, one estimate showed that, globally, there is a surprising 131 spiders per square meter! While this sounds like a worryingly large amount some areas contain densities of 1,000 or more spiders in just one square meter (I really need to tidy my shed!). So, with so many spiders out there (25 million tons if you were to weigh them all!), it is only fair to assume they get through quite a lot of food.
Most spiders eat insects although some larger species will eat lizards, birds, and even small mammals. Biologists accept that spiders will consume an average of 10% of their body weight in food per day – which is like the average man eating nearly 20 pounds of meat every day!
By taking these figures, Nyffeler and Birkhofer estimated that the world’s spiders eat a phenomenal 400-800 million tons of prey each year! This is more flesh than the amount consumed by the 7 billion humans on the planet (who eat around 400 million tons of meat and fish each year), and more shockingly more than the estimated biomass of all the humans on earth (at around 360 million tons!).
That’s right, spiders could eat every person on earth and still fancy something else to snack on!
Fortunately for us, spiders are actually doing us a favour by eating that amount of insects, bugs, and flies – which we don’t really want flying around the place anyway…
Let’s just hope they don’t change their diet anytime soon!