# Weird Science: Spiders Could Eat Everyone and Still Want Dessert

Last updated June 15, 2017 at 1:02 pm

Topics:

Our spider friends do a pretty great job of clearing up the environment for us, getting rid of all sorts of pesky bugs and insects. This makes life more comfortable for us, less pests, less flies, and less bugs inside the house. But how much do they really eat? Do they make that much of a difference?

Two biologists took up the question and came out with a staggering answer. They calculated the world’s spiders eat somewhere between 400 and 800 million tons of prey every year. If you’re wondering, humans eat about 400 million tons of meat and fish – so the spiders are eating at least the same amount as us.

To come to this conclusion they considered how many spiders there are estimated to be in the world, and the average amount of food spiders of different sizes consume. The average density of spiders is thought to be around 131 per square metre, which is terrifying itself when you realise that must mean that there are some areas where the number is far higher. According to the study if you weighed all those spiders it would come to approximately 25-30 million tons. That’s the equivalent of nearly 500 Titanics. Of spiders.

They then averaged that spiders eat around 10% of their body weight every day (that’s like a person eating 8kg of meat every day). Do the maths and you realise the horrifying reality that spiders eat much more than 400 million tons every year.

As well as their efforts reducing insect numbers, they also do a pretty great job of scaring the living bejeezus out of us by hiding behind doors or on car mirrors. So what would happen if they decided to turn their attention to eating the 7 billion humans instead?

Spoiler: it doesn’t end well. The total mass of all adults on Earth is estimated to be 287 million tons. If we add another 25% to allow for the weight of children it would bring the weight of humans up to around 350 million tons. So if the spiders turned their attention to us they could easily eat everyone on Earth and still be hungry.

With that knowledge on board, have a great sleep tonight everyone!

Ben Lewis
Ben Lewis is the Editor of Australia’s Science Channel, and a contributor to Cosmos Magazine. He has worked with scientists and science storytellers including Jane Goodall, Dr Karl, Brian Cox, Chris Hadfield, Robert Llewellyn, astronauts, elite athletes, Antarctic explorers, chefs and comedians. Ben has also been involved in public events around Australia and was co-writer, producer and director of The Science of Doctor Who, which toured nationally in 2014 in association with BBC Worldwide Australia & New Zealand. Want more Ben? You can hear him on ABC and commercial radio in Adelaide, regional SA, across NSW, and the ACT. He also speaks at universities around Australia on communicating science to the public. Around the office he makes the worst jokes known to mankind.

Science and technology is as much a part of our cultural fabric as art, music, theatre and literature. They play a significant role in our daily lives, yet, in a world dependent on science, we often take them for granted. Australia’s Science Channel believes every citizen has a right, and a responsibility, to be informed, and our mission is to create programs to bring that about.

## Featured Videos

In Class With... Neil deGrasse Tyson
Dr Karl - What question keeps you up at night?
Meet Chax - turning reality virtual
Dr Karl - What causes Hiccups?
Lessons from an astronaut: "We have to teach students how to fail"
SCINEMA 2020 opens with new Indigenous filmmaking award
How technology is changing the future of cancer treatment in Australia
Sean Geoghegan - Meet a Medical Physicist
Bringing Japan's breakthrough cancer technology to Australia
Columbia: NASA blew it
The Face of a Stranger
Where Does Space Begin?
The Rarest Drug on Earth
Why is blue so rare in nature
Ant Sisters
Jeremy the Lefty Snail and Other Asymmetrical Animals
Tracking Snow
Smart Slime?
Good in the machine
Kessler Syndrome: What happens when satellites collide?
Why This Skateboarding Trick Should Be Impossible
Charles Camarda on becoming an astronaut
Alan Duffy on what it took to get humans to the Moon
Do aliens exist? Brian Cox explains
From Apollo to Pulsars: Parkes still dishing out the discoveries
Brian Cox on black holes
Australia's 60,000 years of space history
In Class With… Jane Goodall
Etienne Rastoin-Laplane - What's fishy about the Galapagos?
Kit Prendergast - Flowers to keep native bees buzzing
Rebecca Wellard - Eavesdropping on killer whales
Hossein Tavassoli - Mending broken hearts
Dilan Seckiner - Forensic gait analysis
Samuel Bladwell - A new spin on electronics
Sathana Dushyanthen - The double-edged cancer sword
Dwan Price - Nuts and Guts
Catriona Nguyen-Robertson - Exercise takes your immune system for a ride
Thimo Ruethers - The deadly danger of crocs on a plate
Amanda Tauber - Slamming the brakes on metastatic cancer
Hayley Teasdale – The ball that prevents falls (FameLab Australia 2019 Runner-up)
In the Shadow of a Black Hole
In Class With... Monica Gagliano
In Class With... Brian Cox
Start your FameLab 2019 journey now
Nural Cokcetin - It all starts with FameLab
Erinn Fagan-Jeffries - It all starts with FameLab
Ronald Yu - It all starts with FameLab
Noushin Nasiri - It all starts with FameLab
Grassroots
What is machine learning?
Mythbusting artificial intelligence with expert Anton van den Hengel
Using machine learning to predict medical outcomes
KCLOC
Nature Calls
Mexican Fishing Bats
Bittersweet
Timelapse
Invisible Blanket
Look
The Anomalies: Venom Race
Science Meets Making
Spiral
Looking Out There
Protectors of the Penguins
Astroturf
Virtual Humans
Rancheros del Jaguar
Searching For Dark Matter
Finding prehistoric mega-shark fossils on Victoria's coast
The Grandfather of computers
James Cameron talks science
In Class With.....David Suzuki - The Environment
In Class With.....David Suzuki - Career
Sustainable water use with Doug Green
Why is Indigenous science important?
Vanessa Pirotta - Using drones to collect whale snot (FameLab Australia 2018 Winner)
Toby Hendy - Poking Plants (FameLab Australia 2018 Runner-Up)
Muthu Vignesh Vellayappan - Groovy Patches (FameLab Australia 2018 Audience Choice)
Taryn Laubenstein - The Tail of Two Fishes
Richard Charlesworth - Coeliac disease diagnosis can be a pain in the posterior
Pegah Maasoumi - Solar Windows
James Wong - Breathing while you hop: How do kangaroos do it?
Ben McAllister - The ORGAN Experiment: Shining a light on dark matter
Mortaza Rezae - Empowering beautiful minds
Zane Stromberga - Can allergy drugs beat bladder disease?
Working In.....Art - Astrophotography
What's the best way to move - springs or muscles?
FameLab Australia Semi-Final Highlights
Saving lives with platypus milk
Australian astronomers witness death throes of a cocooned star
How Australia's politicians see our future in space
Keeping satellites in the loop
Tim Jarvis & Tim Flannery talk Climate Change
Andy's Week in Science - robo baby, university rankings, and cancer on circadian rhythms
From chocolate factory to surgery - the milliDelta robot
Andy's Week in Science: video games, low tech transition windows and a new CRISPR technique
Science lessons useful in Art Restoration career
Are drones the future of racing?
The future of esports according to the experts
Seeing is believing with artist Eugenie Lee
The human impact of Art Science collaboration
Zoz on 3D Printing
Flavia Tata Nardini on women in engineering
Flavia Tata Nardini on the future of the internet
Explore the ocean floor and Antarctic biodiversity
Artists on Science
What is Space Archaeology?
Scientists on Art
3D Printing in Medical Research
Ethical Issues
Problem Solving - Robotics at Dermatec
Problem Solving with CSI
Tamarah King - Earthquake Geologist
True or False with Bajo and Rad BONUS ROUND
True or False with Bajo & Rad
Andy's Week in Science - Cats vs Dogs
FameLab 2018 - Get Involved!
Nural Cokcetin - How FameLab changed my life
Erinn Fagan-Jeffries - How FameLab changed my life
Noushin Nasiri - How FameLab changed my life
Ronald Yu - How FameLab changed my life
Alan Duffy's Top 5 Science Communication Tips
A Judge's Top Tips for FameLab Australia
Brain Candy - Why, Why, Why Michael Stevens?
The Past, Present, and Future of Malaria
This is a video of poo pills being made!
Mind Games - Sports Psychology
Fuel to Win - Sports Nutrition
Fifty years since Australia beat the world to space
ECR Network: Talk Your Science with Alan Duffy
Andy's Week in Science - chimps, klompen, and clouds
Our robot medicine future - heart huggers and micro biohybrids
Six Awkward Cancer Questions
How do you tell if a whale is left-handed?
She Flies - Turning Girls into Drone Pilots
Andy's Week in Science - Magnetic Fabric, Cancer Treatments, and Echolocation
The Science of Sexuality
Sailing Through Space with Bill Nye
Using Sports Science to Help Olympic Athletes
Three and a Half Minutes of Top Shelf Career Advice
New Space Tech with Andrea Boyd
Kelly Meets the Mars Curiosity Rover
Hearts, Opera, and Tough Conversations - Andy's Week in Science
Bill Nye on Science, Girls, and Saving the World!
2017 Prime Minister's Prizes for Science Part 2
2017 Prime Minister's Prizes for Science Part 1
Who Decides the Law in Space?
Scientists Watch Collision That Created Gravitational Waves
Getting Cold Feet Leads to a Whole New Career
ECR Network - Why Every Scientist Should Be on Twitter - The Benefits
ECR Network - Why Every Scientist Should Be On Twitter - The Fears
Live Podcast - Life Vs Science
Origami Robots, Babies, and Kidneys - Andy's Week in Science
Namira Salim and the Zero-G Peace Summit
Elon Musk's Mars Plan: Expert Analysis
SPACE AF - Thursday
My Time in Space
IAC TV Daily Broadcast - Wednesday
SPACE AF - Wednesday
IAC TV Daily broadcast - Tuesday
SPACE AF - Tuesday
IAC TV daily broadcast - Monday
01:00:41
SPACE AF - Monday
Live from IAC 2017
Brew Ha Ha - Technology Rewrites History
Methamphetamine - Gateway Drug to Parkinson's Disease
Concussion, 3D BioPrinting, and The Universe - Andy's Week in Science
Pulsars, Clearwigs, and Pacemakers - Andy's Week in Science
Revolutions - The Quest to Transform HPV Racing
Brew Ha Ha - Hurricane Irma Blows Away Tesla's Rip Off
Brew Ha Ha - The Limit of Your Lifespan
The Recipient
Think Like a Scientist: Natural Selection in an Outbreak
The End of Snow
The Next Rembrandt
The Spectators
Test Tube Babes
Pangolins in Peril- A Story of Rare Scales
Rock Art Project
Pork.0
OWSIA (Darkened Water)
Nex
Northern Quolls
Dish Life
At Street Level
Custom Love
A Story from Space
Brew Ha Ha - The Most Dangerous Thing in Boxing May Be the Gloves
ECR Network 2017 – Get Interdisciplinary!
01:27:00
Chris Hadfield: The Future of Space Exploration
Brew Ha Ha - Let's Make Algae Australian of the Year
Brew Ha Ha - Australia's Energy Showdown
Nine Awkward Astrophysicist Questions
Brew Ha Ha - There's No Such Thing as an Exercise Pill
National Science Week Awards Show
Brew Ha Ha - Your 5 Step Asteroid Success Plan
National Science Week Forecast
Open Doors. Open Future. Open Day.
Brew Ha Ha - Lose a Little to Gain Millions
Brew Ha Ha - Crowd Sourcing Origami Astronaut Protection
Brew Ha Ha - T-Rex's Prehistoric Power Walk
True or False with Kale Brock
Brew Ha Ha - The Hidden Heroes Tackling Mozzies
Brew Ha Ha - Emergency AI Assistance
Brew Ha Ha - Frogs Forever, Dinosaurs Never!
Brew Ha Ha - Australia, Let's Go To Space
Brew Ha Ha - Welcome to the Microbiome, Archaea!
Brew Ha Ha - Roos Blindside Driverless Cars
Biodiversity of Antarctica Under Threat From Increase In Ice-Free Areas
Brew Ha Ha - The Future of the Census
Tell Me! Brian Cox
Crash, Burn, Tweak, Repeat
Brew Ha Ha - Humans Just Got Older and Wiser
Brew Ha Ha - Cheers to Brain Health?
Gene Therapy Could Cure Allergies
Brew Ha Ha - iHeart Hacking
Ridiculology - New Hubble
Brew Ha Ha - Trees Alone Can't Save Us
Brew Ha Ha - Earth's Accidental Force Field
Dinosaurs on the Big Screen
Brew Ha Ha - Farewell MP3
Kids Beat Grown-ups on Pneumonia Vaccines
Brew Ha Ha - The Booger Conspiracy
FameLab 2017 National Final - Part 2
FameLab 2017 National Final - Part 1
2017 Budget Response
What Are Animal Weapons?
If You Love Both Art and Science, Be a Scientific Illustrator
Getting Personal With Skinks
Brew Ha Ha - CSIRO Email Leaks
FameLab 2017 Western Australia Semi-Final Highlights
Brew Ha Ha - New Hope for Premmies
Brew Ha Ha - Britain Goes Coal-Free
Brew Ha Ha - Naked Mole-Rats (SFW)
Brew Ha Ha - Easter Reminders
Meet Andrea Boyd - Space Flight Controller
Brew Ha Ha - Sperm Drug Smugglers
FameLab 2017 New South Wales Semi-Final Highlights
The Science of Fiction
Brew Ha Ha - Liquorice Poisoning