defragster
Senior Member+
This article lists two other ultrasonic noise makers: recording ultrasonic vocalisations. Though the conclusions agree with the findings here.
I've been seeing this hoping a way to detect the high freq could work - I often go 23 feet to my detached garage at all hours of the night and very earie to detect bats on the periphery against the sky. Last night my cat and I 'detected' one flying around the house. Amazing silent like a butterfly. It ended in an inverted light fixture so I could detach it and got the bat outside. Was so much smaller curled up than when adeptly flying around! He was stunned last night outside but breathing - but seems to have recovered and gone off.
Just searched and found commercial ones for €2102 and EUR 1 725 though they have a EUR 185 basic heterodyne detector
I've been seeing this hoping a way to detect the high freq could work - I often go 23 feet to my detached garage at all hours of the night and very earie to detect bats on the periphery against the sky. Last night my cat and I 'detected' one flying around the house. Amazing silent like a butterfly. It ended in an inverted light fixture so I could detach it and got the bat outside. Was so much smaller curled up than when adeptly flying around! He was stunned last night outside but breathing - but seems to have recovered and gone off.
Just searched and found commercial ones for €2102 and EUR 1 725 though they have a EUR 185 basic heterodyne detector