Real working bat detector!

My bat detectors will let you listen to bat activity around you. They can hear bats to a distance up to about 100 feet away. They will easily sense bats around you. We use them often at home and while camping or on the water kayaking. I have been making and using bat detectors for more than 6 years. This is my latest version, packaged in a plastic box. This bat detector has an orange LED.

This bat detector was made August 31, 2024. The unit you see in the photos is exactly what you will receive. The bat detector was tested and picked up bats flying overhead.

Bats use a remarkable high frequency system called echolocation to hunt for insects in the dark. Echolocation works in a similar way to sonar. Bats make calls as they fly and listen to the returning echoes. A bat can tell how far away something is by how long it takes the sound to return to them. These calls are usually at a frequency too high for humans to hear naturally. This detector digitally divides that high frequency so that humans can hear it. Just set it on a table outside at dusk and listen. In the early evening, you can often see the bats that are detected.

Using the bat detector is easy.

There are two switches and a volume control. One switch controls the power, the other is a dimmer for the LED. Turn the detector on, adjust the volume control, point where you expect bats. It is good to place the detector standing upright on a flat surface. Holding in your hand is fine, but you must keep a firm grip on the detector to avoid making noise. Audio from this bat detector is not very loud! It is plenty for a few people together who may be talking but maybe not so good for a large party. You may notice that your detector can hear sounds other than bats. There are insects that will become audible with the detector, as well as man made sounds.

I understand that pet rat giggles can be heard with bat detectors, not tested by me but sounds interesting! Look here for info on rat giggles: www.scientificamerican.com/video/eavesdrop-on-ultrasonic-rat-giggles/

This bat detector is built in an inexpensive plastic box to keep your cost down. I make other versions in copper boxes, they cost almost double of the plastic versions simply because of the packaging. This unit works just as well for less cost!

There is a standard 9 volt battery inside. Battery should last at least 12 hours, up to about 30 hours. Any kind of standard size 9 volt rechargeable or one time use 9 volt battery should work fine.

How does a bat detector work?

This bat detector works by picking up the ultrasonic sounds made by bats (also other creatures and things) via a microphone, the sound then goes through two stages of amplification with a little high pass filtering. The signal then goes to a digital chip which divides the audio by 16 resulting in a sound that can be heard by humans. That signal then goes through a filter to make it sound a bit better and remove some of the high frequency sound to avoid feedback. After that a volume control, then a standard amplifier drives the speaker.