Meadow katydids (Orthoptera: family Tettigoniidae, genus Conocephalus) are small (1–2 cm) grasshopperlike insects that congregate in late summer on low bushes and tall grass near ponds where males then emit calls to attract females. These sounds are entirely ultrasonic, consisting of sequences of brief (20–25 ms) bursts, repeated at 30 ms intervals, of 10–20 clicks separated by 1–1.5 ms within each burst. Each click covers frequencies of 20–90 kHz. The same frequencies are used for sonar by big brown bats (Eptesicus fuscus), which frequent the same ponds while hunting for prey and nearly always fly in audible range of the meadow katydids but do not attempt to capture any of them. Calls of several male insects usually overlap at slightly different inter-click intervals so that the acoustic waveform wavers, thus creating moving virtual acoustic sources for the bat’s binaural listening. Aggregate calling is virtually continuous at sound pressures exceeding 90–100 dB SPL at distances of 1–2 m. Neuronal recovery-times in the bat’s auditory system are ∼0.5 ms to accommodate reception of closely-spaced echolocation emissions and multiple echoes, so click bursts will reliably evoke volleys of responses at successive stages of the bat’s auditory pathway, preempting biosonar echoes received by approaching bats.