TIL: If Spiders Unified They Could Eat Us All (And Still Have Room ...

An interesting and nonetheless alarming video happened to pop on my Facebook feed the other day:

If spiders worked together, they could eat all humans in a year

Jeez! Are you kidding me?

Unfortunately, I'm not! After tons of research and studies, scientists have concluded that those disgustingly lovely creatures have the potential to devour human population within a year... actually, less! And they would still be hungry after that.

Be nice to them, you know if they ever joined together, they could eat us all!

Don't be afraid, spiders mostly feed on arthropods (other insects), more rarely earthworms, slugs, snails and small vertebrates. They occasionally present incidents of cannibalism (feeding on spiders of other species), and sometimes complement their menus with vegan dishes.

The conclusions of a recent study

English W.S. Bristowe and Canadian A.L. Turnbull joined their efforts in a study to finally suggest that:

The total global spider biomass equals 25 million metric tons fresh weight.
The total global spider prey biomass equals 400–800 million tons per year (and that's "about 1% of the global terrestrial net primary production"). Of course the variety and prey consumption percentages vary geographically and correspondingly to each species.

Compare it with the total human consumption of "400 million tons of meat and fish annually" and you'll see that spiders have a greater appetite than us.

Ok, they eat a lot, but humans are bigger

You think you're all greater than a spider? In Greek we say "Η ισχύς εν τη ενώσει", which means there is strength in unity. A study in 2005 has shown that the global human adult population is about 287 million tons. Compare it with the 400-800 million tons of spider food yearly and you'll see that if spiders ever decided to change their eating habits we wouldn't be able to fill their tiny stomachs. Even if they could get their jaws on children, who make another 70 million tons, spiders would still need more food to satisfy their appetite.

Original image from: pixnio.com

Why do we need them?

To haunt our lives. Another study has shown that spiders are found in every house on the planet. Like the ghosts of your past, they will find you no matter how many hours you spend cleaning every week.

But despite being hateful to many, spiders are really important for the balance of the food chain. Preying on insects, they help controlling their populations. Moreover, certain species have evolved morphologically and behaviorally in order to protect themselves from spider-hunters. Not to mention that some insects reduce food consumption in the presence of spiders, in order to stay protected (you can say that spiders work like a natural pesticide).

Spiders also serve as lunch for parasitoids and other species like birds, frogs, newts, mice, lizards, bats and even fish.