Have you ever wondered how a tiny insect can make a sound loud enough to be heard across an entire field?
The answer lies hidden beneath the soil. Male mole crickets do not just dig burrows to hide in – they are master engineers. Using their shovel-like front legs, they carve out special horn-shaped tunnels that act as underground loudspeakers. When a mole cricket stands at the narrow end of his burrow and chirps, the shape of the tunnel amplifies his mating call, sending it hundreds of metres into the night air.
It is a brilliant piece of natural acoustic engineering. And the best part? You can recreate this secret science right in your own home.
How to build a megaphone burrow (step-by-step)
In this simple sound experiment, we are going to build our own megaphone burrow and test how different shapes change the way sound travels. It is a perfect screen-free activity that blends biology, physics, and a little bit of cardboard construction.
What you need
You probably have everything you need for this experiment sitting in your recycling bin right now. Gather these supplies before you begin:
One large piece of thick card or an empty cereal box
One cardboard tube (like a toilet roll or kitchen roll tube)
Sticky tape
Scissors
A mobile phone (to play a constant sound, like a ringtone or alarm)
A towel or small blanket
What to do
Step 1: Set your starting volume
Ask a grown-up to help you find a constant sound on a mobile phone. A ringing alarm or a continuous beep works best. Place the phone flat on a table and listen carefully to how loud it is. This is your baseline volume.
Step 2: Test a straight tunnel
Take your cardboard tube and place it standing straight up over the phone’s speaker. Put your ear near the top of the tube. Does the sound seem louder or quieter than before?
Step 3: Build the megaphone burrow
Now let’s build the mole cricket’s special shape. Cut your thick card into a large semi-circle, then roll it into a cone shape – wide at one end, narrow at the other. Tape it securely so it holds its shape. The narrow end should be just wide enough to fit over your phone’s speaker.
Step 4: Test the cricket's design
Place the narrow end of your cone over the phone’s speaker and stand back. Is the sound louder now? Try pointing the wide end in different directions. Does the sound travel further when it is focused through the cone?
Step 5: Add the soil
Mole crickets dig their burrows in the earth, which naturally absorbs some sound. Wrap a towel loosely around the outside of your cone to act like the soil. Does the towel change how the sound escapes?
The Science: what is really happening?
When a phone (or a mole cricket) makes a sound, the sound waves spread out in all directions. A horn-shaped burrow stops those sound waves from escaping sideways. Instead, it bounces them off the cone walls and forces them all to travel in one direction.
This focuses the sound energy, making it much louder and allowing it to travel much further. It works exactly like a cheerleader’s megaphone, but built entirely out of dirt by an insect no bigger than your thumb.
Try this next
Ready to take your acoustic engineering to the next level? Try these three challenges to see how different variables affect your sound:
Challenge
What to Test
What to Observe
The Distance Test
Leave the phone playing through the cone and walk backwards.
How many steps can you take before the sound fades away?
The Shape Test
Try making a wider cone and a narrower cone.
Which shape makes the best amplifier?
The Material Test
Build a new cone out of thin paper instead of thick card.
Does the thin paper work as well as the thick card?
The natural world is full of hidden wonders like the mole cricket's burrow. From the deepest oceans to the soil beneath our feet, there is always something new to discover when you know where to look.
Ready to uncover more of nature's secrets?
If your child loved this experiment, they will be captivated by Eco Kids Planet magazine. Every issue is packed with real science, wild discoveries, and hands-on projects that turn curiosity into action.
Try your first 3 issues for £6 and start their next adventure today.
This competition asked you to design a secret egg hidden somewhere in nature, and your entries went far beyond the obvious nests and burrows. Eggs arrived disguised as pine cones, floating on leaf boats, perched on volcano ledges, tucked into cloud cover and even masquerading as chocolate Easter eggs to fool foxes. Thank you to every reader who took up the challenge and thought like a parent bird, fish, reptile or imaginary creature trying to keep their precious egg safe.
We were swept away by the response to this competition. Letters arrived from rivers across the world – the Thames, the Mississippi and many more unnamed waterways – each one brimming with personality, passion and a genuine love of the natural world. You gave your rivers voices that were worried, hop...
Our Risky Moment competition invited young explorers to capture a risky moment in the wild – a split second when animals must make bold choices to survive. From daring leaps across rocky cliffs to dangerous river crossings, we received many hair-raising entries showing just how adventurous life in nature can be.
