Earth has no shortage of amazing animals—and those animals have no shortage of incredible sounds. They bark, screech, hiss, and make a whole assortment of noises that can chill a person to the bone. Here are 11 animals whose terrifying sounds will stop you in your tracks.
1. Barn Owl
When we think of the sound an owl makes, most people instantly think of a distinct hoot, like the hoo-h’HOO-hoo-hoo of a great horned owl or a barred owl’s classic who cooks for you. You may be surprised by the call of a barn owl, which isn’t gentle and doesn’t sound anything like a charming hoot. The birds emit a hair-raising shriek to communicate with other barn owls or scare away predators. The widespread species (they live on every continent except Antarctica) also makes an evil-sounding hissing noise that seems like it comes from a horror movie.
2. Red Fox
The popular 2013 song “What Does the Fox Say” didn’t really answer the question its title poses—perhaps because the things a fox says wouldn’t match the upbeat tune. Red foxes may look pretty, but the sounds they make are anything but. These animals scream, bark, howl, and squeal. Most often, they make a raspy barking sound that they use to communicate with other foxes. They’re often most active at night, so you’re most likely to hear—and be terrified by—these sounds after dark.
3. Howler Monkey
The howler monkey has one of the loudest calls of all land animals, letting out low-pitched growling sounds at dawn or dusk. Their vocal cords are powered by their large larynx and throat. The thundering chorus sounds more like a roar than a howl—the Houston Zoo even compares it to the noise of a garbage disposal—and can be heard up to three miles away. The Central and South American monkeys are, however, less loud during the daytime hours: 80 percent of their day is spent resting.
Giraffes are fascinating creatures that vocalize in several different ways. They grunt, snort, whistle, and hiss, and even make coughing sounds. They also emit an eerie, sustained hum at a low-frequency (about 92 hertz, on the low end of what humans can hear). Giraffes only make this sound at night, so scientists have proposed it’s a way for the animals to communicate in the dark when they can’t see each other. When amplified, the humming is strikingly similar to the haunting sounds you’ll often hear in a ghost movie.
5. Great Blue Heron
Great blue herons have been on our planet for a long time: The oldest fossil discovered of the species is from the Pleistocene Epoch, or about 1.8 million years ago. Today’s Great Blue Heron has “prehistoric” characteristics: a long bill, powerful, curved neck, long legs, and creepy a dinosaur-like squawk that can last for up to 20 seconds. The large bird, which has a height of five feet and a wingspan of 5.5 to 6.6 feet, makes its home near shallow waters of swamps, marshes, lakes, and rivers of North and Central America. If you’re ever near water and you hear a primordial noise that makes you stop in your tracks, you may have heard the grating call of a Great Blue Heron.
6. Mountain Lion
If there’s one sound that would make your heart rate skyrocket when walking through the forest, it’s the searing scream of a mountain lion. Interchangeably referred to as a puma, panther, or cougar, the mountain lion is a species of wild cat that lives throughout North and South America. It has the largest range for any non-human mammal in the Americas, with its habitat stretching from Canada all the way to South America. The cat lets out its frightening sound to communicate with other mountain lions, when amid a mating cycle, or when it feels threatened.
Elk, one of the largest species in the deer family, can be found throughout North America. They make an incredibly loud sound that’s technically called a “bugle,” but it can often sound more like a roar or a screech. The animals use the call during mating season and to claim territory—and no one would blame you for mistaking it for a scream.
8. American Alligator
Male American alligators let out deep, bone-chilling bellows to signal to other gators just how big and bad they are—and the bigger the alligator, the deeper the bellow. Gators can rumble so deep they create vibrations and large ripples in the water. The American alligator’s habitat extends throughout subtropical waterways from North Carolina to Texas and Florida, so you’ll want to be on high alert if you hear its reptilian roar while in those areas.
9. Common loon
Common loons, water birds that inhabit the lakes of the U.S. and Canada, have several distinguishable calls that make for a great jazz soundtrack. The most haunting are the wail and yodel. The wail—a soulful and eerie call that sounds like a wolf howling at the moon—is a way for them to check in with their mate, and is commonly heard at night when they can’t make visual contact with one another. The yodel is a more aggressive call that only males make, and it’s unique to each bird. Their calls are so piercing that the mournful wails of a single loon can travel across a lake to reach the ears of anyone in the vicinity.
10. Tasmanian Devil
Shrieks, screams, growls, and snorts are only a few of the sounds that come out of the Tasmanian devil, the largest carnivorous marsupial in the world only found in Tasmania, an island south of Australia’s mainland. A Tasmanian devil’s sounds aren’t the only scary thing about it: The species has the strongest bite-for-size than any other mammal. They’re so strong they’ve been known to bite through metal, and when they eat their prey, they devour it bones and all. Sadly, the Tasmanian Devil has been listed as endangered due to habitat destruction and a contagious tumorous cancer that has spread through the species.
11. King Cobra
The king cobra makes a terrifying, low-pitched, raspy hiss that sounds like a combination of a growl and a deep breathing sound. The snakes can grow to 12 feet long, but in some instances are known to reach 18 feet long, and they live in the forests, bamboo thickets, or swampy areas of India and southern Asia. King cobras are extremely venomous but generally stick to eating cobras (thus, their name). Despite its reputation as a dangerous snake, the king cobra will only attack people when cornered, in self-defense, or when protecting its eggs. Its chilling hiss is a sign to stay away.