Good afternoon We have a number of AudioMoth 1.2.0 with firmware version 1.8.0 or 1.8.1. and we use them to record bats. Until recently they worked fine, but gradually they started producing thousands of nonsense tiny files (39-61 kb) and only a handful of good ones scattered here and there, even in areas with many bats. In some cases they produce only the tiny ones, and no big/good files at all. The settings are the same as before (see end of message for an example). Yesterday I tried one device with settings in the audible range and it worked well (on my desk). Then I used the usual settings for ultrasounds and put it outside overnight - today I found out that the problem was still there. We are trying with new alkaline batteries like Energizer and sd cards suggested by Open Acoustics Any ideas how to solve it? Thanks in advance Sample rate (Hz) : 384000 Gain : Medium Sleep duration (s) : 1 Recording duration (s) : 5 Active recording periods : 2 Recording period 1 : 00:00 - 03:30 (UTC) Recording period 2 : 14:30 - 24:00 (UTC) Earliest recording time : ---------- --:--:-- Latest recording time : ---------- --:--:-- Filter : Band-pass (11.0kHz - 144.0kHz) Trigger type : Amplitude Threshold setting : -32 dB Minimum trigger duration (s) : 0 Enable LED : Yes Enable low-voltage cut-off : Yes Always require acoustic chime : No Use daily folder for WAV files : No Disable 48Hz DC blocking filter : No Enable energy saver mode : No Enable low gain range : No