Item from Dune by Frank Herbert
A rhythmic vibration device driven into the sand to attract sandworms — used as a diversion during spice harvesting or to summon a ride across the desert.
The thumper is beautifully simple — a clockwork device that does one thing: make rhythmic noise in sand. But that one thing is enough to summon the most powerful creature on the planet. Sandworms are attracted to rhythmic surface vibrations — it may mimic prey, or simply trigger a territorial response. A thumper draws worms from across a wide area, and they will investigate the source with single-minded determination. This makes the thumper indispensable for two purposes: diversion (plant a thumper to draw worms away from your actual position) and transportation (plant a thumper, wait for a worm, mount it with maker hooks). The timing matters. Plant the thumper, move away using sandwalk (arrhythmic gait that doesn't attract worms), take cover, wait. The worm arrives in minutes. After that, you're either riding it or running from it, and on open sand, you can't outrun a sandworm.
A meter-long stake with a spring-loaded hammer mechanism at the top. Planted vertically in sand, the mechanism produces a deep, rhythmic thumping at regular intervals. Simple, rugged construction — no electronics, no power cell, just mechanical clockwork and a heavy striking head. The sound it produces is felt more than heard: a deep pulse that travels through sand for kilometers.
Also known as: sand thumper, worm caller