You’re sitting on your porch at twilight when something flickers past your head. It’s silent. Or at least, you think it is. Most people assume bats are these ghostly, mute creatures of the night, but the truth is way noisier. If you could hear everything they were "saying," the night sky would probably sound like a construction site full of jackhammers and smoke detectors.
So, what noise does a bat make exactly?
It depends on who’s listening. To us, it’s mostly silence punctuated by the occasional high-pitched "tick" or a frantic "scritch-scratch" coming from the attic. To another bat, it’s a constant stream of data, insults, and GPS coordinates. We’re basically standing in a room where everyone is screaming, but we’ve only got our ears tuned to a tiny fraction of the frequency.
The Sound You Aren't Supposed to Hear
Most bat sounds are ultrasonic. That means the frequency is higher than the 20 kHz limit of the human ear. While we’re stuck in our low-frequency bubble, bats are blasting out pulses that can reach 120 decibels. To put that in perspective, that’s as loud as a chainsaw or a rock concert. If we could hear it, we’d need earplugs just to walk through a park at dusk.
They do this for echolocation.
💡 You might also like: AP Bio Parents Guide: Why Your Kid is Stressed and How to Actually Help
The bat lets out a series of clicks or chirps. These sounds hit an object—like a juicy moth or a brick wall—and bounce back. By timing the return, the bat builds a 3D map of its world. Dr. Brock Fenton, a legendary researcher in the bat world, has spent decades explaining that this isn't just "seeing with sound." It’s more sophisticated than our best military sonar. They can detect a single human hair in total darkness.
Chirps, Squeaks, and Clicks
When you actually can hear them, it usually sounds like a very sharp, metallic clicking. Imagine taking two pebbles and tapping them together really fast. That’s a common sound for the Big Brown Bat or the Little Brown Bat when they drop their frequency just enough for human ears to catch the tail end of the pulse.
Then there are the "social sounds."
Bats are surprisingly chatty. When they’re jostling for position in a roost, they don't use ultrasound; they use audible squeaks. It sounds like a cross between a bird’s chirp and a mouse’s squeak. It’s argumentative. Honestly, if you’ve ever heard a colony of Mexican Free-tailed bats, it sounds like a bunch of tiny, angry old men bickering over a checkers game. They’re literally telling each other to move over or "that's my spot."
Why the "Social" Noises Matter
Researchers at Tel Aviv University, specifically Professor Yossi Yovel, have done some incredible work decoding these noises. They used machine learning to listen to thousands of hours of Egyptian fruit bat calls. It turns out, bats aren't just making random noise. They communicate specific information.
- Gender Identification: They can tell if another bat is male or female just by the tone of the squeak.
- Food Squabbles: They have specific calls that mean "hey, that’s my fruit."
- Space Issues: They complain when someone gets too close in the huddle.
It’s not just "noise." It’s language, or at least a very complex version of social signaling. When you ask what noise does a bat make, you have to realize you’re asking about a creature that spends half its life talking.
The Sound of the Hunt: The Terminal Buzz
If you’re lucky enough to have a bat detector—a cool little gadget that translates ultrasound into sounds humans can hear—you’ll notice a rhythm.
Click... click... click...
That’s a bat cruising. It’s looking for something.
Click-click-click-clickclickclickclick!
That’s the "terminal buzz." When a bat finds an insect, it ramps up its call rate to get a high-resolution "image" of the moving target. It sounds like a tiny engine revving up or a zipper being pulled fast. The moment that buzzing stops? That’s usually when the moth met its end.
Misconceptions About Bat Noises in the House
"I hear thumping in my walls."
Usually, that’s not the bat’s voice. Bats weigh next to nothing—a Little Brown Bat is about the weight of a quarter. They don't "thump." If you hear heavy thumping, you’ve probably got a raccoon or a very confused squirrel.
Bats make noise in houses through scratching. Their little claws on wood or drywall sound like dry leaves blowing across a pavement. It’s rhythmic and frantic. If they get stuck, they might emit a series of "distress" squeaks. These are definitely audible to humans. They’re high-pitched, piercing, and sound incredibly stressed. Kind of like a dog whistle that's slightly broken.
The Wing Flutter
Sometimes the noise isn't vocal at all. If a bat is flying in a confined space, like your living room (it happens), the sound is a soft, leathery whap-whap-whap. It’s much quieter than a bird. Birds have stiff feathers that cut the air; bats have skin membranes that are remarkably silent. You usually feel the air move before you hear the wings.
Do All Bats Sound the Same?
Nope. Not even close.
The Hoary Bat has a deep, scratchy call that sounds like a cricket on caffeine. The Spotted Bat actually has a call so low that most humans with decent hearing can hear it without any equipment. It sounds like a high-pitched "tseee-tseee" every few seconds.
Fruit bats are a whole different ballgame. Since they don't rely on echolocation to find stationary fruit (they use smell and big eyes), they don't make the constant clicking. Instead, they make loud, raucous cackles and squawks that can be heard from blocks away. If you’re in a tropical area and hear what sounds like a pack of monkeys in a tree at 2:00 AM, it’s probably fruit bats.
How to ID a Bat by Sound
If you’re serious about figuring out what’s flying over your backyard, you can actually get "bat recorders" for your smartphone. These plug into the charging port and use a specialized microphone to capture frequencies up to 100 kHz.
Apps like Echo Meter Touch visualize the sound. You’ll see a "search phase" call which looks like a hockey stick on the graph. The shape of that curve tells you exactly which species is visiting. It’s like birdwatching, but for nerds who like the dark.
Practical Steps for Identifying Bat Sounds
If you think you have bats and want to confirm it by sound, here is what you should do:
- Listen at "the magic hour." This is 15 to 30 minutes after sunset. This is when they are most vocal as they emerge from their roosts.
- Check the corners. If you hear scratching in your attic, don't just look; listen for the "chatter." If you hear tiny, bird-like chirping during the day, you likely have a colony roosting.
- Differentiate the scratch. Mice "scamper" (fast, light footsteps). Bats "scrabble" (claws digging into a vertical surface).
- Use a bat detector. If you’re an enthusiast, investing in a basic heterodyne detector is a game changer. It turns the "silence" of the night into a symphony of pops and whistles.
- Look for the "guano" evidence. If you hear the noises, check the ground below the noise source. Small, dark pellets that crumble into sparkly dust (insect wings) confirm that the "noise-maker" is indeed a bat.
Dealing with bats requires a bit of nuance. They are protected in many areas because they eat millions of mosquitoes. If you hear them in your house, don't panic. They aren't trying to chew through your wiring like rodents do. They’re just looking for a warm place to sleep. Usually, the "noises" they make are just them living their lives, unaware that we’re even listening.
Understanding the complexity of bat vocalizations changes how you see the night. It’s not a quiet void. It’s a dense, loud, and incredibly social world, operating just one frequency above our own.
To properly handle a bat situation if the noises are inside your home, wait until the fall when they typically migrate or move to hibernacula. You can then seal the entry points with foam or caulk. Just make sure they're all out first—nobody wants a silent house that turns into a smelly one because a bat got sealed in.
Next Steps:
Identify the frequency. If the sound is constant and rhythmic, check for insects like katydids first. If the sound is erratic, "scratchy," and occurs primarily at dusk and dawn, look for staining or droppings near your roofline to confirm a roost.