There are many beautiful islands located around the world, and while some are known for their perfect weather conditions and pristine beaches, others are known for their remote location and relaxed way of life. But there are also islands that are unique and interesting because they have become known for their unusual animal populations, which often far outnumber the human inhabitants (if there are any at all because no one wants to live on an island filled with venomous snakes).

The stories of how these animals came to live on these islands vary, some are the subject of folklore, others were once considered sacred beasts, and then there are those that are invasive species which simply hitched a ride on a ship -- and many wish they hadn’t because they’ve affected the ecosystem and overrun the island.

Below are 20 islands, many of which draw tourists to them because of their tame population of really adorable creatures, from swimming pigs to sika deer. This offers an opportunity to interact with adorable animals we wouldn’t typically get to experience every day. And then there are some islands that are best avoided because the population of snakes or rats have made a nuisance of themselves.

20 Aoshima In Japan Has Become Famous For It's Cute (And Hungry) Cat Population

Cat lovers will be interested in Aoshima, Ehime, the island that is home to so many cats that they outnumber humans by 6 to 1, Favy reports. Japan Today notes that there are 130 felines on the island, but just 13 permanent residents, most of them elderly, with an average age of over 75.

The island has also been in the media on numerous occasions because it has become a popular tourist destination, but Japan Today notes that in order to feed all the cats an organization has been set up to ask for donations.

19 Rabbit Island, Or Ōkunoshima, Is Definitely One Of The World's Cutest Places

You may not want to visit an island that is overrun by moose or mice, but a visit to an island filled with adorable bunnies is definitely appealing. This is the Japanese island of Ōkunoshima’s claim to fame, as it’s known to be home to hundreds of feral rabbits, which is why it’s often referred to as Usagi Jima (or Rabbit Island), Smithsonian reports.

So, how did so many rabbits come to live on this island in the Seto Inland Sea? According to the publication, their existence is a bit of a mystery, although there are many theories, including one that states they were once the test animals for a secret poison gas operation.

18 The Swimming Pigs Of Big Major Cay Is One Of The Most Magical Sightings

The pigs that can be found on Big Major Cay, Bahamas (which has also become known as Pig Beach) are truly special because these creatures swim in the water. The island is uninhabited by humans but has become a popular tourist spot for those who want to see the pigs.

According to Travel + Leisure, the visits from tourists have changed the behavior of the pigs because now instead of foraging for food, they are more likely to approach humans who feed them or throw them food from their boats.

17 There Are Millions Of Red Crabs On Christmas Island Which Color The City During Migration

The Australian territory known as Christmas Island is an interesting place, home to some very interesting inhabitants; the red crab (identified by their bright red color). There are 14 species of crab found on the island, but the Christmas Island website notes that the red crab are the most “obvious,” and around 40 to 50 million of these crabs call the island their home.

They are most noticeable during migration when they can be seen making their way to the sea. According to National Geographic, every year, millions of crabs move from the island’s interior rainforests, towards the sea, where they lay eggs and breed.

16 Wallabies Can Be Found In An Unexpected Place: Lambay Island In Ireland

When you think of wallabies, you would typically associate this marsupial with Australia, and it’s surrounding islands, which National Geographic notes are their primary location. So, it may come as a surprise to know that there is an island dedicated to wallabies, in Ireland.

Lambay Island is a private island home to wild wallabies, and according to Smithsonian, the conditions of the rocky island have proved to be “almost perfect” for these animals. If you were wondering how a group of wallabies came to live on the island, then apparently that’s because the wealthy Irish family, the Barings, decided to raise wallabies in the 1950s and 1960s.

15 Hawaii's Kauai Is Home To Many Roaming, Wild Chickens

On Hawaii’s island, Kauai, there is an abundance of chickens, which roam the streets and run wild. Live Science notes that there are thousands of feral chickens, which were once domesticated but have since reverted to a wild state and have bred with the “remnants of the Polynesian junglefowls.”

According to Kauai Blog, most locals believe that the chicken population expanded after 1992 when a hurricane destroyed chicken coops and released domesticated hens and roosters. They can be seen in large numbers, wherever a source of food is near.

14 Montecristo Is Dealing With A Rat Population That First Arrived After Stowing Away On Ships

The island of Montecristo, off the coast of Tuscany in Italy, is not filled with cute bunnies or cats, instead, it has been overrun with rats. According to Daily Mail, the uninhabited island has become filled with black rats, which are believed to have first got there after stowing aboard boats bringing tourists to see the island.

The publication notes that only around 1,000 tourists are granted access to the island each year. The rats have become a problem for the island (with a reported one rat per square yard), and authorities are trying to figure out a way to eradicate the population, without harming marine life.

13 Guam's Animal And Plant Life Are Being Ruined By The Brown Tree Snake

Equally unappealing is an island overrun with snakes, and this is what has happened to Guam. According to Science Alert, the island is filled with venomous brown tree snakes, which are believed to have been accidentally introduced to the island in around 1944, when they hitched a ride onboard a military vehicle traveling from Papua New Guinea.

The snake population has gotten out of control (with more than 2 million snakes living on the island) and has affected the bird and rodent life on the island, as well as the growth of new trees, which the publication notes “could be falling by as much as 92 percent.”

12 Cape Fur Seals Have Made Seal Island Their Home, And Great White Sharks Lurk In The Waters Surrounding It

There is an island in False Bay, South Africa, that is home to around 75,000 cape fur seals, Lonely Planet reports. This spot has become a popular tourist attraction, with visitors taking a boat trip out to see the seals, but, if you're going between the months of May to September, you may also spot another creature, the Great White shark.

The waters of the island are teeming with Great Whites because they feast upon the seals, and according to Dive Discovery, it is one of the only places to see multiple predatory events each day. Cool for shark fans, not so cool for the seals.

11 Rottnest Island In Australia Has The Largest Population Of Quokkas (Arguably The Cutest Animal To Ever Exist)

Quokkas are perhaps the cutest creatures to ever exist, and they exist in large numbers on Rottnest Island, Australia. The Quokka is the only mammal native to the island, and according to the Rottnest Island website, the island is home to the largest population -- around 10,000-12,000 of these nocturnal cuties.

All plants and animals on this island are protected by law, and the island serves as a conservation area. Those who do not adhere to the rules (including feeding wildlife) can be charged thousands in fines.

10 Tonawanda Island Has A Bit Of A Cat Problem On Its Hands

The 85-acre Tonawanda Island in New York is home to hundreds of stray cats, and, unfortunately, this population was first started by people who abandoned their pets, Syracuse notes. The cats are also causing a problem for the human inhabitants (and Oddity Central notes there are more cats than humans living here) as they are getting into the marina boats.

Measures have been taken to curb the cat population by getting them spayed or neutered, and while adult cats will be able to continue living on the island, the kittens have been put up for adoption.

9 Japan's Miyajima Island Is A Fantastic Place To Walk Side-By-Side With Tame Deer

A trip to Japan’s Miyajima Island will be one that is truly unforgettable because it’s filled with tame deer. According to Business Insider, there are more than 1,000 sika deer living on the island, most of whom are located in the 500-hectare Nara Park.

The sika deer were considered sacred in Japanese folklore, and although they no longer have a sacred status, the publication notes they remain protected today. Visitors to the island can come close to the deer, which are so tame that they allow humans to feed and pet them. They can also be seen walking the streets alongside humans.

8 Monkey Island Off The Coast Of Puerto Rico Has Served As A Place For Scientific Research For Over 90 Years

Monkey Island (or Cayo Santiago) is a small island located off the coast of Puerto Rico and has served as a location for scientists to research primates since the 1930s. According to The Independent, the rhesus macaques species were brought to the area, where they thrived, with their population reaching over a thousand. However, Hurricane Maria has affected their existence, destroying much of the vegetation which they feast upon.

Scientists have been working on a solution to save and care for these monkeys, whose loss of habitat has endangered their survival.

7 Access To Brazil's Snake Island Is Forbidden Because Of The Venomous Snakes That Live Here (Not That You Wanted To Go)

Another island overrun with snakes (and one we never plan to visit) is Ilha da Queimada Grande, or, as it’s more commonly referred to, Snake Island, in Brazil. This island is home to a large population of Golden Lancehead Viper, and according to Atlas Obscura, there is an estimate of between 1 and 5 of these snakes per square meter.

Keeping this in mind, it’s little wonder why no humans call this island home (in fact, they are forbidden), especially because these snakes are venomous -- this species of snake is “responsible for 90 percent of Brazilian snakebite-related fatalities.”

6 Assateague Island Is A Remarkable Place Filled With Wild Horses (But Don't Get Too Close)

Horses roam free on Assateague Island, and according to NPS, they are feral (meaning that they were once descendants of domesticated horses, but have reverted to a wild state).

They are believed to have first come to the island in the late 17th century, by people attempting to avoid taxation of livestock. However, the local folklore would have individuals believe that these horses are descendants from horses who survived a shipwreck off the Virginia coast. Putting their history aside, this is considered to be one of the few places in the United States were tourists can see wild horses (although they are cautioned not to get too close).

5 The Green Iguanas In Grand Cayman Have Made A Nuisance Of Themselves

Grand Cayman is home to many Green Iguanas, so many, that they can be found everywhere on the island, and have made a bit of a nuisance of themselves. The Economist notes that there are around 61,000 people living on Grand Cayman, but the number of Green Iguanas far outnumbers these humans and there are more than 6,000 per square kilometer.

The iguanas do not have any natural predators on the island (although are often run over) and were initially brought to the island around 25 years ago as pets, the publication reports.

4 Cape Shiriya Is Home To Wild Horses That Can Survive In Extreme Cold

Another spot to see wild horses is in the town of Cape Shiriya. According to Japan Travel, the town is located in the northeastern point of the island of Honshu, an area that can experience extremely cold temperatures, yet the wild horses that live here able to withstand them. The publication notes that these horses are referred to as the "Kandachime," which means “to stand in the cold.”

En Aomori notes that these horses are protected and because they can survive the extreme winters, they serve as a lesson about the power of life.

3 Runde Island Is Home To A Large Population Of Atlantic Puffins

If you want to travel to a destination that is filled with puffins, then Norway’s Runde Island is the perfect spot. Runde is a small island located in Herøy, and is home to the “the southernmost seabird colonies in Norway,” Runde Centre reports. In addition to large populations of Atlantic puffin, there are also several other bird species that can be found here.

The island is not accessible by main roads but is a popular destination among birdwatchers who enjoy hiking the cliffs in the summertime.

2 Gough Island Is Overrun With House Mice, Which Are Feeding On Seabird Chicks

Gough Island is overrun by house mice, and their presence on the South Atlantic island has had an effect on multiple species of seabird chicks, which these mice feed off. The seabird chicks are defenseless, which make them the perfect prey for the mice on this island. According to Financial Times, they are not your average cute little mice either because this strain has grown much larger.

According to Phys, The Royal Society for the Protection of Birds notes that 2 million seabird chicks are being affected by the mice population on this island, and because of this there are attempts to eradicate the mice.

1 The Human Population In Norway's Ylvingen Are Outnumbered By Moose By Two To One

Another island that is overrun by animals is Ylvingen in Norway, which is home to many moose. So many moose, that according to News In English, local Norwegian newspaper, Brønnøysunds Avis, reported that the population of moose outnumber humans by two to one.

Moose typically tend to avoid humans, but the moose on this island are so used to humans encounters they no longer flee for the woods, which is worrying to locals because their children or pets may be in danger of being trampled by these large creatures.

References: Runde Centre, Financial Times, Phys, News In English, Favy, Japan Today, Smithsonian, Travel + Leisure, National Geographic, Kauai Blog, Live Science, Daily Mail, Science Alert, Lonely Planet, Dived Discovery, Business Insider, The Independent, Atlas Obscura