Echolocation jamming

Bats avoid this type of jamming by producing short sounds of 3–50 ms when searching for prey or navigating.

[4] Bats produce progressively shorter sounds, down to 0.5 ms, to avoid self-jamming when echolocating targets that they are approaching.

Another form of jamming occurs when an echolocating animal produces many sounds in succession and assigns an echo to the wrong emission.

To avoid this type of jamming, bats typically wait enough time for echoes to return from all possible targets before making the next sound.

[12] However, the tiger moth Bertholdia trigona produces clicks at a very high rate (up to 4,500 per second) to jam bat echolocation.

[14] The possibility that moths jam bat echolocation arose with an experiment report published in 1965 by Dorothy Dunning and Kenneth Roeder.

[12][20][21] In the 1990s experiments were conducted broadcasting clicks to bats performing echolocation tasks on a platform[22] and with neurophysiological methods[23] to demonstrate a plausible mechanism for jamming.

[13] In this study big brown bats were raised in captivity to ensure they had no prior experience with clicking prey and trained to attack moths tethered to a thin line attached to the ceiling in an indoor flight room.

[27] In a 2022 report, bats are found to change their emission lengths to defeat high duty cycle jamming.

However, scaling up acoustic deterrents to large volumes for applications such as keeping bats away from wind turbines is difficult because of the high atmospheric attenuation of ultrasound.