Bat Echolocation and Bat Detectors
What exactly is a Bat Detector?
A Bat Detector is a simple, handheld device that listens to the frequencies that bats use to hunt and find their way at night. It converts these frequencies to tones and clicks that humans can hear. Think of it as translator. Most Bat Detectors are the size of a pack of cigarettes and have a special microphone that picks up the echolocation calls of bats.
How Easy is the
Belfry Bat Detector to Use?
It is so simple and
easy anyone can use the Belfry Bat Detector! Follow these instructions:
1. Get out your
Belfry Bat Detector.
2. Turn it on.
4. It's just that easy.
bats sound like on a Bat Detector?
The answer to
this question depends on the exact species of bat in your area, but
basically you will hear a series of clicks, tocks and smacks that vary
in rhythm, duration and structure. You will hear the ever present and
amazing "feeding buzz" as a bat closes in on a flying insect and
finally devours it. High intensity bat calls will be heard as small
screams or chirps. Bat calls vary greatly and there is
much information "hidden" in these short burst of sound energy. Using
a personal computer (PC) with a bat detector allows you to record and
then "slow down" these bats calls.
Click here to listen to a small brown bat recorded on a laptop PC using our Belfry Bat Detector with audio out jack.
the best place to use a Bat Detector?
Bats are usually
found where there are flying insects. Wooded areas and bodies of
freshwater are excellent places to hear bats. You may hear many bats
at one time. You never know where you may find bats. Where I live,
there are some trees, but lots of blacktop and concrete. I often see
bats flying by at night. It is surprising the places bats turn up and
the only way to know is to go out looking and listening for them.
bats most active?
Bats are most active
after it gets dark. I have found that about 3 hours after sunset to
about 6 hours after sunset offers the greatest activity. However,
going out to find and listen to bats just 15 to 45 minutes after
sunset allows you to still see them against the early night sky.
Seasonwise, you won't
hear bats during the winter if you live in a colder area. Bats
hibernate during the winter and are active during the Spring, Summer
and very early Fall. If you are lucky enough to live in a warmer area
with mild winters, you'll find bats are active all year. No matter
where you live on colder days, when the temperature is around 45
degrees farenheit, bats will not fly at all.
using a Bat Detector attract bats to me?
No. A Bat Detector is
simply a listening device. It works very much the same way a portable
radio does, except instead of listening to radio stations it listens
to bats. Any bats you listen to will ignore you and go about their
using a Bat Detector upset bats in any way?
there are many human activities that are reducing bat populations and
destroying their habitats, but using a Bat Detector is not one of
I get a Bat Detector?
International sells units for about $250.
I build Belfry
Bat Detectors to order for $64.95. Each unit is fully
functional and ready to go.
Please click here to
see more information on our products for bat enthusiasts.
your Belfry Bat Detector design better than the other Bat Detectors?
Most other Bat
Detectors I have seen require the user to "tune" the detector to the
proper frequency and then you can only hear that one frequency.
Different bats use different frequencies, so you could tune one of
these detectors to 40 khz and completely miss a bat flying around
using 25 khz!!! Furthermore, the same bat can use a wide range of
frequencies in its search for insects.
My design converts
practically the entire frequency range that bats use, about 20 to 100
khz. This way, you don't need to fuss with knobs. Simply turn the unit
on and sit back while listening to all the bats in your
area. The unit contains a small speaker so many people can listen at
once and it runs for many hours on a 9 volt battery.
record bat calls using your Belfry Bat Detector?
Yes. We offer an
option for $10 that will add a 1/8 inch monaural audio out jack. This
is a high impedance output that may be connected to a tape recorder, a
laptop PC (personal computer) with soundcard or even an amplifier for
large group demonstrations.
How can I
use a PC to record bat calls with your detector?
Just plug a
cable into the Belfry Bat Detector's audio out jack and the other end
to the soundcard on your PC. Then, you'll need a software package to
capture the calls.
Click here to
dowloand a free, shareware sound analysis program, called Spectrogram,
that I find very useful. Click your Browser's BACK button to return
here when finished downloading.
To learn more about how we use Spectrogram and to see some sample bat calls prcoessed using this free shareware, click here.
Bats are truly
amazing creatures. Most people know exactly what a bat is and what it
looks like, yet there are many myths surrounding bats that simply
aren't true. Bats are not blind, they are not flying rodents, they
won't get tangled in your hair and usually they do not bother people.
However, they do have an amazing ability that scientists and the
military have been trying to uncover for more than 100 years. They can
see using sound - this is known as echolocation or
Even though bats have
strong eyesight, they are nocturnal creatures that spend their waking
hours flying at night in almost total darkness. They are easily able
to avoid obstacles and feed on insects using their biosonar. A bat can
readily eat 1,000 mosquitoes in about an hour using echolocation.
Bats use their
biosonar in a sound or frequency range that humans cannot hear. Human
hearing spans from about 200 hertz (or 200 cycles per second) to
20,000 hertz (or 20,000 cycles per second). Bats can hear well into
the ultrasonic range or up to roughly 200,000 hertz.
Their biosonar operates from about 25,000 to 100,000 hertz,
abbreviated as 25 to 100 kilohertz or khz (thousand hertz).
It may be a good
thing that we cannot hear bats because their biosonar can be quite
loud. Echolocation calls can range from 100 decibels (or db) to about
60 db. 100 db is approximately equivalent to a smoke detector alarm
and 60 db is about the sound level of a human conversation. If you
live in the USA, you most likely have little brown bats and big brown
bats in your area. These are examples of bats that are loud, in the
100 db range, and use a frequency of about 25 to 35 khz.