Somewhere I kept an issue of a Pop - Sci Mech? I saw - with pic of a lethal sound generator the French built. For warfare natch. At humongous levels @ ~54 Hz IIRC - shakes guts to bits, 4x Hz - anal sphincter gives up yada
Your guess, the resonant freq. of fire-ant abdomens - surely up there; maybe KHz. Sustained 100 W audio with heavy (lead sheet?) sound absorber over back (facing the world) - might be as effective as \ufffdwaves. Voice coil may need cooling. Hi power amps now dirt cheap. Experiment on a few - belly up? You got the dB level and the freq.
Hey - it's science..