The United States has over 700,000 miles of public sewer pipes, enough to wrap around the Earth 28 times. Every day, people flush billions of gallons of wastewater into the sprawling subterranean system.
This is joined by rainwater, funnelled through the storm drains. With a high concentration of household and human waste, the sewers of America aren’t an obvious refuge for wildlife, yet many species can be found there. Some are accidental visitors. Others more deliberate. Here are 10 species found in America’s sewers.
10 USA sewer dwellers
Alligators
If you listen to the stories that swirl around the sewers of New York, the pipes are home to a thriving community of ‘sewer alligators.’ Not true! Although the odd pet might find its way into the underground pipes, the environment there is far too cold and polluted for them to survive.
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Florida, on the other hand, is a different story. In 2024, researchers deployed 39 cameras in 33 sites in the sewers of Gainesville and left them running. Writing up their finds in the Urban Naturalist, they were amazed by the diversity they recorded. Thirty five different species were identified, including the American alligator.
Most of the sites where alligators were recorded were sections of sewer that pass under roads, known as culverts. So, the scientists think the reptiles were using the channels to avoid crossing roads and move safely between ponds. In some recordings, the alligators seemed to be cornering fish into dead-end tunnels. So, the alligators may also be using this manmade ecosystem as a hunting ground.
Yellow-bellied Slider
The yellow-bellied slider is a semiaquatic turtle, native to southeastern United States, where it is the most common turtle species. As the name suggests, they have a yellow belly that is buried under a domed carapace of murky brown river hues.
Also known as basking turtles, for their love of soaking up the sun, adults can grow to the size of a dinner plate. They are commonly kept as pets, but their true habitat is in the wild, in freshwater swamps, marshes and ponds.
Sewers do contain a high percentage of fresh water, but it is heavily contaminated. No matter. In the Gainesville study, yellow-bellied sliders were the second-most photographed reptile, after alligators. Twenty-seven recordings were taken, with the turtles favouring a handful of locations where there was always water present. Like the alligators, the sliders also seemed to be using the pipes as corridors to travel between ponds, showing that sewers can have a positive effect for some of the animals that frequent them.
Raccoons
If you live in the US, you’ll know there are very few places where raccoons don’t poke their button noses. Bins, attic spaces, liquor stores… so, of course, they’d find their way into the sewers.
Raccoons frequently use urban sewer and storm drain systems for shelter and travel, leading to occasional dramatic recues when the animals become trapped. In one memorable, YouTube-worthy incident, firefighters and wildlife experts helped to rescue a raccoon that had its trapped head poking out of a in a sewer grate in Wilmington, North Carolina.
In the Gainesville study, raccoons were spotted more often than any other species. Cameras snapped around 1,800 images of them, but the raccoons had the last word. Some of the cameras were mounted to the underside of manhole covers, where the last footage they ever took was of a raccoon ripping the camera down.
Rats
Of course, American sewers have rats. Show me an old, urban sewer network that doesn’t! Whilst the underground pipes aren’t everyone’s ideal home, for rats, sewers offer warmth, water, food and a relatively safe space from predators.
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Last year there even was talk of a ‘Ratgmageddon’. Rats, it was claimed, are overrunning our cities, with record numbers recorded in Washington, San Francisco and New York. Scientists have linked the population increase to climate change, because warmer cities make more attractive homes for rats.
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Whilst the exact number of US sewer rats is unknown, it’s thought there are around 3 million living in New York alone. This is a problem, because rats can spread disease. Leptospirosis (Weil’s disease) is transmitted via their urine, and hantavirus can be spread by inhaling infected droppings. Not without reason then, that the US spends roughly $18 billion per year dealing with them.
Snakes
In September 2017, workers from the Sewer Department of Worcester, Massachusetts, were making a routine inspection of a storm drain, but when they lifted up the manhole cover, they found 1.5 metre-long python, curled up underneath.
With help from experts, the snake was soon relocated to a local rescue centre, but the incident left people wondering how it got there in the first place. Unlike Florida’s sewer alligators and North Carolina’s raccoons, pythons are non-native. The nonvenomous snakes hail from Africa, Asia and Australia, but they are kept as pets.
The most likely explanation then, is that a pet snake went awol. Elsewhere, there are reports of native snakes have slithered into sewers via storm drains. Last year, for example, wildlife enthusiasts rescued a northern watersnake from a storm drain in New Jersey where it nearly drowned.
Manatee
Manatees or ‘sea cows’ are large marine mammals that eat seagrass. They can’t live in sewers, but they can get stuck in them.
In February 2026, a worker at Florida’s Melbourne Beach spotted a 185 kg manatee trapped in a storm drain. To be precise, the gentle giant was stuck in a baffle box, which is a large chamber built into a sewage system, designed to separate out debris, sediment and other unwanted items. It did its job well. The manatee, which must have swum into the structure through the storm drain, was wedged in tight.
In the end it took multiple fire rescue units, officials from the Florida Fish and Wildlife Service, experts from the University of Florida and mechanics from a local car-tow business to haul out the manatee in a sling and then relocate it to SeaWorld Orlando. The manatee is now recovering.
Myotis bats
It may come as a surprise to find that bats, flappy mammals known for flitting around above ground, can also be found in some sewers.
There are more than 100 species of myotis or mouse-eared bats. These are small, insectivorous beasties, which tend to roost in caves and trees. In Gainesville, Florida, however, where researchers rigged up dozens of cameras inside the sewers, Southeastern Myotis bats were seen hanging around.
This was not a rare event. Hundreds of bats were caught on camera. Many were roosting, but some were spotted swooping down to the sewer floor to capture insects. This suggests that the bats aren’t just sleeping in the sewers, they’re actively foraging there too.
In Poland, myotis bats are known to use storm sewers as maternity sites, so it’s possible that bats exploit sewers far more often than is realised. We’ve just never noticed before.
Carolina Wrens
Some birds frequent the sewage system too. Think about it. It makes perfect sense. Sewage may be just waste to us, but it’s a magnet to the flies, cockroaches and other invertebrates that can digest its organic content. And what eats insects? Birds, of course!
Above ground, lots of birds visit the open air treatment pools at the sewage plants where waste is treated. Orange-crowned and black-throated green warblers, for example, have been seen near the sludge digesters at Brooklyn’s Spring Creek pollution plant.
Some birds, however, go underground. Carolina wrens are perky little flappers, common across the Eastern US. In the Gainesville study (yes, that again), Carolina wrens were observed at six locations, sometimes with nesting material in their beaks. This hints, either that the birds are collecting building material from the sewers, or possibly even nesting there. More cameras in more sewers are required to figure this out!
Nine-banded armadillos
Here are some fun facts about the nine-banded armadillo. One, when it’s frightened, it jumps up to a metre in the air - a literal jump scare. Two, females give birth to genetically identical quadruplets. This is an odd reproductive strategy that seems to work well for them. Three, they don’t always have nine bands. Anywhere between seven and eleven is just fine. And four, you guessed it, sometimes they live in sewers.
The nine-banded armadillo is native to North, Central and South America, where it lives a solitary, nocturnal life chomping on insects and other invertebrates. In the Gainesville study, which, you don’t need me to tell you, is the best snapshot that we have of American sewer wildlife, the armoured mammals were seen trundling around drainage tunnels.
Eastern spadefoot
Amphibians love a bit of land. And they love a bit of water. It is, perhaps, no surprise then, that they can be found in America’s sewers, where both types of habitat exist. Native species, such as southern toads and pig frogs, have been documented, as have some non-native species, such as the Cuban tree frog.
The eastern spadefoot toad is endemic to the eastern United States, where it is said to prefer places with loose, sandy soils, that are good for burrowing. So, imagine the surprise of researchers, when they spotted the big-eyed beauty in… drum roll… the sewers of Gainesville.
Rather than breeding in the sewers, however, it’s thought the toads that were photographed had fallen into a storm drain. So, bravo to the scientists behind the Gainesville study, for telling us more about the diversity of America’s sewage wildlife, than anyone else before them.
