6 Snakes as Big as Humans that Could Invade the United States

Written by Andrew Wood
Updated: February 16, 2023
© Heiko Kiera/Shutterstock.com
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Snakes are fascinating creatures that come in many different shapes and sizes. Some species are small enough to fit in the palm of your hand, while others can grow to be as big as a human. A few species are capable of growing to truly enormous sizes. In this article, we’re going to look at six species capable of eating a human that are already on the loose and getting well-established in Florida. So just avoid Florida, right? Not so fast. The US Geological Survey has predicted that some of these species could thrive in 1/3 of the United States . . . maybe even as far north as Washington D.C.!

Read on to learn more, including the environmental impact, what is being done to fight back, and how you can be a responsible buddy to a snake if you choose to keep one of these fascinating but deadly creatures as a pet.

Boa Constrictor

What Do Boa Constrictors Eat - Boa on Tree
Boa constrictors can grow to be quite large, with some individuals reaching lengths of up to 13 feet and weighing up to 90 pounds.

©Jan Hejda/Shutterstock.com

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The boa constrictor is a large, non-venomous snake found in a wide range of habitats throughout Central and South America, as well as some islands in the Caribbean. They live in a variety of environments such as rainforests, deserts, and grasslands, and are highly adaptable and can thrive in both arid and humid conditions.

Boas frequent water sources and are excellent swimmers. They are also good climbers and like trees, rocky outcroppings, and caves. Opportunistic feeders can survive on a wide variety of prey, including small mammals, birds, and reptiles. They are nocturnal and spend most of their time hiding in crevices or under rocks during the day.

Boa constrictors can grow to be quite large, with some individuals reaching lengths of up to 13 feet and weighing up to 90 pounds. They have large, irregularly shaped dark brown or reddish-brown blotches on a lighter background. These blotches camouflage them so they can blend in with their surroundings.

Boa constrictors do not naturally occur in the wild in the United States. They either escape from pet owners or are released. Boas have been cited in many counties of Florida, especially in the south and central parts of the state, but in some counties bordering Georgia and Alabama as well.

Hawaii is an ideal snake environment, but because of its isolation from the mainland, it has no indigenous snake species. In order to protect the state’s unique, delicate habitat, Hawaiians have made owning a pet snake illegal – a crime that may result in a $200,000 fine and three years in prison. Nevertheless, a few boas have been found in Hawaii in recent years. State officials are now battling a least seven invasive snake species that have been accidentally or maliciously introduced to the environment.

Burmese Python

Burmese Python, Boa Constrictor, Snake, Aggression, Brown
Burmese pythons, some reaching 26 feet, are already well-established in Miami-Dade, Monroe, and Collier counties in and around the Everglades, and have been sited as far away as southern Georgia.

©iStock.com/Lunatic_67

The Burmese python (Python bivittatus) is a species of large, non-venomous snake native to Southeast Asia. It is one of the largest species of snake in the world, with some individuals reaching lengths of up to 26 feet (8 meters). The Burmese python is named after its native range, which includes parts of Burma (Myanmar) and other countries in Southeast Asia. It is a carnivorous species and feeds on a variety of animals, including rodents, birds, and even small mammals.

The Burmese python has a distinctive pattern of tan, yellow, and brown scales, which are arranged in large, irregular blotches. The snake is a powerful constrictor and is capable of killing its prey by wrapping its body around it and squeezing until the prey can no longer breathe. The Burmese python is generally not aggressive toward humans, but it can be dangerous if provoked or threatened. In the wild, the Burmese python lives in a variety of habitats, including rainforests, swamps, and grasslands. It is also sometimes kept as a pet. However, it is important to note that these snakes can be challenging to care for due to their large size and special care needs.

Burmese pythons are already well-established with large breeding populations in Miami-Dade, Monroe, and Collier counties near the Everglades. They have also been sited as far away as southern Georgia. They were first discovered on the loose in 1979 and were thought to be unwanted pets released by their owners. In 1992 Hurricane Andrew destroyed an exotic pet breeding facility and released a large number of this species into the wild. Since then, their numbers have exploded to 100,000 or more. Florida wildlife officials have become alarmed at the rapid decline of prey species in the ecosystem. For some small mammals, populations have dropped as much as 90%.

Green Anaconda

anaconda snake
There have been about 11 sightings in Florida of the green anaconda, the largest species of snake in the world, with some individuals reaching lengths of up to 30 feet and weighing up to 550 pounds.

©Mark_Kostich/Shutterstock.com

The green anaconda (Eunectes murinus) is a species of large, non-venomous snake native to South America. It is a member of the boa family, Boidae, which also includes pythons and boa constrictors. The green anaconda is the largest species of snake in the world, with some individuals reaching lengths of up to 30 feet and weighing up to 550 pounds. It is a carnivorous species and feeds on a variety of animals, including rodents, birds, and small mammals.

The green anaconda is named for its distinctive green coloration, which is accented by black, brown, or yellow markings. It is a powerful constrictor that wraps its body around prey until the creature can no longer breathe. The green anaconda is generally not aggressive toward humans, but it can be dangerous if provoked or threatened. In the wild, the green anaconda lives in a variety of habitats, including rainforests, swamps, and grasslands. Due to its potentially enormous size, it does not make as good a house pet as some other species and is most often encountered in zoos or other institutions.

There have been about 11 sightings of green anacondas in the wild in Florida, as far north as Gainesville and as far south as Miami. Most of the sightings have been around the central parts of the state. Researchers do not think they have become firmly entrenched in the environment yet. Even so, this relatively small number of sightings is alarming, given the danger and aggressive nature of this predatory snake.

Reticulated Python

Animals That Molt - Reticulated Python
The reticulated python can grow to 30 feet and has been spotted mainly in southern and southwestern counties of Florida but also in Tampa and on the Georgia border.

©Mark_Kostich/Shutterstock.com

The reticulated python (Python reticulatus) is a species of python native to Southeast Asia. It is one of the largest species of snake in the world, with some individuals reaching lengths of up to 30 feet. The species has a distinctive pattern of black, gold, and white scales, which form a reticulated (or net-like) pattern on the snake’s body.

The reticulated python is a non-venomous snake and relies on constriction to subdue its prey. It is a carnivorous species and feeds on a variety of animals, including rodents, birds, and even small mammals. In the wild, the reticulated python lives in a variety of habitats, including rainforests, swamps, and grasslands. Although they are pets in some parts of the world, they can become a difficult and expensive problem to manage when they grow too large.

Reticulated pythons have been observed in the wild in multiple counties of Florida, but not in the large numbers or widespread geographic distribution as some other large invasive snake species. They have been spotted mainly in the far southern and southwestern counties of Florida. However, they’ve also been sighted in the Tampa area on the Gulf coast of Central Florida. There have also been a few sightings as far north as the Georgia border. Geographically isolated individuals like this are thought to be pets accidentally or intentionally released.

Rock Python

African rock python curled up with head in air
Researchers believe rock pythons, which can reach up to 20 feet, have been established in Florida since the early 2000s.

©Chris Graf/Shutterstock.com

The rock python (Python sebae) is a species of large, non-venomous snake native to sub-Saharan Africa. It is the largest snake found in Africa and is one of the largest species of snake in the world. Some individuals reach lengths of up to 20 feet. The rock python is named after its preferred habitat, which includes rocky outcroppings and cliffs. It is a carnivorous species and feeds on a variety of animals, including rodents, birds, and small mammals. The rock python has a distinctive pattern of brown, black, and white scales, which are arranged in large, irregular blotches.

The rock python is a powerful constrictor that suffocates its prey by wrapping its body around it and squeezing. The snake is generally not aggressive towards humans, but it can be dangerous if provoked or threatened. The rock python is found in a variety of habitats, including savannas, forests, and grasslands. It is widely distributed throughout sub-Saharan Africa. While sometimes kept as a pet like other giant snake species, it can become unmanageable as its size increases.

Researchers believe rock pythons have been established in Florida since the early 2000s. They have been identified in Miami-Dade and Sarasota counties, but so far only in a small localized area. Among the snakes found were a pregnant female and two hatchlings. This shows that the species has established a wild breeding population.

Yellow Anaconda

Yellow Anaconda
So far sightings of the yellow anaconda, which can grow to lengths of 20 feet, have been confined to the Florida Everglades in the US.

©Chris Tefme/Shutterstock.com

The yellow anaconda (Eunectes notaeus) is a species of large, non-venomous snake native to South America. It is a member of the boa family, Boidae, which also includes pythons and boa constrictors. The yellow anaconda is one of the largest species of snake in the world. Some individuals reach lengths of up to 20 feet (6 meters). It is a carnivorous species and feeds on a variety of animals, including rodents, birds, and small mammals.

The yellow anaconda is named for its distinctive yellow coloration, which is accented by black, brown, or green markings. It is a powerful constrictor capable of killing its prey by wrapping its body around it and squeezing until the prey suffocates. The yellow anaconda is generally not aggressive towards humans, but it can be dangerous if provoked or threatened. In the wild, the yellow anaconda can be found in a variety of habitats, including rainforests, swamps, and grasslands. It is important to note that keeping these snakes as pets can be challenging due to their large size and specialized husbandry needs.

Yellow Anacondas have not been spotted as much in Florida as other large snake species, but they have been seen in the Everglades. Their numbers are not yet large.

How is Florida Fighting Back?

As you can see from this list, Florida is ground zero for multiplying giant snake species. The vast majority live in the Everglades where relatively few people are active. However, they do sometimes show up in suburban areas, particularly if pet owners released them in populated areas.

While all the snakes on this list are non-venomous and tend to retreat from encounters with adult humans, they will attack if provoked or if particularly aggressive during breeding season. Their teeth can inflict severe lacerations and introduce disease-bearing bacteria, and if they lunge hard enough, they can break bones. Pets and small children are in real danger of being stalked as prey by these powerful animals. Even a grown human adult can be killed if the snake is able to get its coils around their neck or torso.

Besides their potential to hurt people, invasive species such as this can have a huge adverse ecological impact. With no natural predators able to hunt them over land, water, and in the trees, they can multiply virtually unchecked. These kinds of snakes sometimes lay 3 clutches of eggs a year with 50-100 eggs in each. It is difficult to make precise estimates of how many invasive large snakes now live in the wilds of Florida. Experts suggest the collective total could be anywhere from 100,000 to 1,000,000.

Wildlife officials have to admit that completely eradicating all these snakes is unrealistic. At this point the most they hope for is to control their numbers so they don’t completely drive prey species to extinction. Already, populations of raccoons, opossums, and other small mammals are down as much as 90%. Endangered species, such as the Key Largo woodrat, are greatly threatened. Left unchecked and growing to full size, they can also threaten the survival of larger prey, such as deer, wild boar, the Florida panther, and maybe even black bears.

Humanely killing pythons in Florida is legal and encouraged. One way officials locate large breeding females is to release males equipped with radio trackers during the breeding season. Because the males seek out the largest females, game officials have been able to remove enormous snakes from the environment. One of these, dispatched in 2022, was 18 feet long and weighed 215 pounds. Its last meal had been a full-grown white-tailed deer! Florida also stages an annual contest that gives cash prizes of up to $10,000 to people who catch the largest python or the greatest number of them.

How to be a Responsible Snake Owner

Considering a pet snake? Given the potential dangers these large species can represent to people, pets, and the environment, consider keeping a smaller non-venomous species and enjoy the big constrictors in the zoo. But whatever species you choose, here are 10 tips to keep in mind as a responsible snake owner:

  1. Research the specific needs of the snake species you plan to own, including their dietary, habitat, and temperature requirements.
  2. Provide your snake with a suitable and appropriate enclosure that meets its needs.
  3. Feed your snake a varied diet that is appropriate for its species and size.
  4. Keep the enclosure clean and maintain proper hygiene to prevent the spread of disease.
  5. Provide your snake with a hide box and other items to provide them with a sense of security.
  6. Keep the enclosure’s temperature and humidity at the appropriate levels for your snake’s species.
  7. Handle your snake gently and with care.
  8. Seek out a veterinarian who is experienced in treating snakes, in case your snake needs medical attention.
  9. Do not release your snake into the wild. It may not be able to survive or may cause harm to native wildlife.
  10. Keep your snake’s enclosure secure, so that it cannot escape or be accessed by other animals or children.

What to do with an Unwanted Snake

Dealing with Pet Snakes

If you are a snake owner who feels you can no longer care for your pet, here are a few options to consider:

  • Sell or give away your pet to a new owner who is thoroughly aware of what is involved in the responsibility and able to provide proper care.
  • Investigate the policies of snake rescue organizations or your local humane society and make arrangements to drop off your snake there.
  • If the laws in your state permit killing snakes of this species, research ways to humanely euthanize your snake. This is best done with the help of your veterinarian.
  • Under no circumstances should you release a non-indigenous snake into the wild, in consideration of danger to humans, pets, and the ecosystem.

Dealing with Wild Snakes

If you encounter a snake on your property or in the wild, take one or more of these steps:

  • Back away, remove children and pets from the area, and do not try to capture or kill the snake yourself.
  • If it is possible to do so without getting close, take a photo of the snake to aid in identification. If it is moving, keep it in sight without getting too close until authorities arrive to remove it.
  • If you are familiar with snake species and recognize it as an indigenous, non-venomous species, leave it alone. Let it go about its business, as you would a bird or squirrel.
  • If you think it is a non-venomous invasive species, do not try to handle it. Even if it is a species popularly kept as a pet, an individual born in the wild may be considerably more aggressive than one that is accustomed to being handled.
  • If the snake is venomous, an invasive species, or just unwanted on your property, call the animal control number in your area to have it professionally removed.
  • If the laws in your state permit, you are within your rights to kill some snake species humanely. Before doing so, you should be familiar with the species that live in your area. Check laws of your locality.

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Burmese Python in a tree
Burmese Python is a species invasive in the Everglades.
© Heiko Kiera/Shutterstock.com

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About the Author

I'm a freelance writer, world traveler, and lifelong animal lover. Currently, I'm an "Emotional Support Human" to 4 dogs, 1 cat, and 2 guinea pigs. My favorite wild animal is the quokka, the most selfie-friendly animal in the world!

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