Bat Deterrent Systems
DETAILS
HOW IT WORKS
The deterrent system emits an ultrasonic acoustic field in the same range as bats’ natural calling frequencies. This interferes with their ability to receive and interpret their own echolocation calls and creates a disorienting airspace that is difficult to navigate. By jamming their echolocation systems in such a way, bats are discouraged from entering the treated airspaces and roosting locations.
NO DETERRENT
Bats emit a high frequency call that is dispersed throughout the atmosphere, then reflect off of objects, including their prey. As the call travels away from the bat it spreads, causing the initial energy emitted to cover a larger and larger area. In this example we see that the call reflects off a moth, and travels back to the bat. The echo return suffers the same spreading losses as the outgoing signal, so the returning echo is very faint compared to the initial call. Bats rely on hearing this echo to determine how long it took the call to reach the object and bounce back, which provides information about how far away the object is.
WITH DETERRENT
The NRG Bat Deterrent Systems create constant ultrasonic noise at the same frequency as the bat call. When a bat enters the airspace where the deterrent units are operating, the ultrasound from the deterrent units will be louder than the echo return the bat is listening for. This effectively “jams” the bats ability to hear its own return. If the bat can’t hear the echoes, it is unable to successfully forage and orient itself, so it chooses airspace without the ultrasonic noise.
The video above shows a pond test of NRG's Bat Deterrent Systems. The Deterrents were turned on for 5 minutes and then off for 5 minutes multiple times. The left-hand side shows the bats’ flight paths (green dots) when the Deterrents were off, while the right-hand side shows the bats’ flight paths (red dots) when the Deterrents were on. As seen in the video, there was a significant reduction in the amount of bat activity when the Deterrents were on.