Bali's Wildlife: A Safety Guide to Spiders, Snakes, and Other Hidden Hazards

Bali's idyllic weather and lush landscapes create a paradise for Instagram-worthy photos and a thriving habitat for diverse wildlife, including animals, insects, and reptiles. However, it's important to remember that not all of Bali's creatures are as welcoming as its people. Here's what you need to be cautious of on this paradise island.

In cartoons and Disney movies, monkeys are often depicted as cute and harmless creatures, playfully frolicking around. However, the reality in Bali is quite different. Monkeys here are clever, mischievous, and sometimes aggressive, especially when they are in groups.

These monkeys are known for their boldness, snatching anything that catches their eye—food, water bottles, glasses, phones, earrings, you name it. In places like the Monkey Forest in Ubud, there are even rumors that some monkeys collaborate with locals, stealing items and returning them for a reward.

If you plan to visit areas inhabited by monkeys, exercise caution. Keep shiny or valuable items out of sight, as these can easily attract unwanted attention. Remember, monkeys have sharp teeth and can carry diseases, including rabies, which is deadly without proper vaccination. If you're bitten by a monkey—or any animal—seek medical attention immediately, even if the wound appears minor.

Balinese dogs, often called "balidogs," aren't always the friendly companions you might expect. These dogs can carry a variety of diseases, including scabies, demodicosis, fungal and bacterial infections, fleas, and lice. While it's uncommon to contract these illnesses, it's wise to wash your hands thoroughly after touching a dog.

Balidogs also pose a hazard on the roads. They have a peculiar habit of lying in the middle of streets, especially at night, making roads like the one from Canggu to Ubud particularly risky for scooter riders.

Like other dogs, balidogs can be aggressive and may bite. They become even more dangerous when in packs. For instance, there was an incident where a pack of balidogs attacked an Australian tourist.

Additionally, despite efforts by Bali authorities to vaccinate stray dogs, rabies remains a concern with balidogs. If you're bitten by a balidog, even if the wound seems minor, it’s essential to see a doctor promptly, as you may need to undergo a series of rabies shots.

Though cats may seem like ideal cuddle companions, they can transmit various diseases, including ringworm (dermatophytosis), feline scabies, fleas, lice, and even toxoplasmosis—a parasite humorously said to make people love cats unconditionally. Cats can also carry and spread rabies. To protect yourself, always practice good hygiene after touching any animal, especially strays.

Bali is home to about 46 snake species. While their hissing and slithering might seem intimidating, only six are truly dangerous, including the king cobra, kraits, pit vipers, and vipers. Most other snakes, though potentially venomous, are not usually fatal. Generally, snakes are more afraid of humans and will only attack if provoked. If you encounter a snake in your home, call a professional service to handle it—don't attempt to deal with it yourself, as snakes are quick and dangerous. Having a cat may help keep them away.

To minimize the risk of snake bites in the forest, wear appropriate footwear, use sneakers, and carry a flashlight at night, as snakes avoid light. Remember that snakes are excellent at camouflaging, so you might not see them until they are very close. If bitten, avoid trying to suck out the venom. Instead, keep the affected limb still, seek medical attention immediately, drink plenty of fluids, and, if possible, photograph the snake for identification. This will assist doctors in choosing the correct antivenom. Even if the bite isn’t venomous, it could still lead to an infection, so seeking medical help is always recommended.

When it comes to bees, wasps, and hornets, the best approach is simple: avoid disturbing them or their nests, and they are likely to leave you alone.

Bali is home to many wild and semi-wild bee species. Occasionally, swarms may come close to people's properties, but they typically do not sting unless provoked. If you are stung, follow these steps: check if the stinger is left in the skin and remove it, clean the area with an antiseptic solution, apply a cold compress, and drink plenty of fluids. Taking an antihistamine is also advisable, as allergic reactions can occur.

If you experience any signs of an allergic reaction, especially if symptoms worsen, seek medical attention immediately. This is particularly important if the sting is near the eye, mouth, or throat, as even slight swelling in these areas can be dangerous. Remember that allergic reactions to stings occur in about 2% of people.

Mosquitoes are active year-round in Bali, but their numbers can increase significantly during the rainy season, which typically runs from October to March. The rainy season creates ideal conditions for mosquito breeding due to high humidity and the prevalence of standing water in puddles, water containers, and clogged drains. This environment supports the rapid development of mosquito larvae. In contrast, the dry season from April to September generally sees a decrease in mosquito activity, but mosquitoes can still be a concern, especially if there are sources of standing water around.

Mosquitoes are a common nuisance in Bali and can pose serious health risks, such as transmitting dengue fever. Dengue fever is a serious illness that often requires hospitalization and is common in Bali. For example, early in 2023, Bali reported 2,500 cases of dengue fever. If you experience symptoms such as fever, swollen lymph nodes, a bright red rash, or joint and muscle pain, seek medical attention immediately.

The mosquitoes that transmit dengue fever—primarily Aedes aegypti and Aedes albopictus—are day-active. This means they are most aggressive during daylight hours, particularly early in the morning and late in the afternoon, though they can bite throughout the day.

To protect yourself from mosquito bites and reduce the risk of dengue fever, wear protective clothing, eliminate standing water, and use mosquito nets and screens.

If ants invade your home, act quickly to prevent damage and discomfort. Use a local insecticide like Baygon to eliminate them before they can damage your furniture or steal your food. Ants are incredibly strong—they can carry away parts of your meal and may even bite if their attempts to steal food fail.

Besides being a nuisance, some ants, like mosquitoes, can spread diseases such as dengue fever.

To avoid insect bites while exploring nature in Bali, apply repellents available at local stores like Indomaret and AlfaMart.

Tomcats are small flying insects commonly found in rice fields but occasionally enter homes. Exercise caution if you encounter them—crushing or swatting these insects can result in severe, long-lasting chemical burns. If you come into contact with a tomcat, wash the affected area immediately with soap and water. If some time has passed since the burn occurred, visit a pharmacy, mention "tomcat," and they can provide a special ointment for burns. Although these insects can be aggressive, managing encounters with them is usually straightforward.

Some centipedes in Bali can grow up to 20 centimeters long, and their bites can be extremely painful, though they are not usually fatal. There is no antivenom for centipede bites, so treatment generally involves pain relievers and applying lidocaine to the affected area. Most symptoms should subside within 48 hours, but it’s still a good idea to consult a doctor to ensure proper care.

Bali is home to cockroaches—large, flying insects about the size of a matchbox. While their size might be unsettling, these creatures pose no real harm to humans. If your home becomes infested, it's best to contact a local pest control service, many of which also handle ants and flies.

Bali is home to three species of scorpions, none of which are deadly unless you have an allergy to their stings. If you are allergic, you'll know quickly, as reactions can be severe.

If stung, try to take a photo of the scorpion to assist doctors with treatment. Even if you're not allergic, a scorpion sting can be extremely painful and may cause local paralysis. It's important to seek medical attention in either case. For children or elderly individuals who are stung, seek medical help immediately, as scorpion stings can be particularly dangerous for them.

After a sting, wash the affected area with soap, apply a cold compress, take an antihistamine, elevate the limb to heart level, and use a pain reliever.

Bali doesn’t have any spiders that are dangerous to humans, but it does host some impressively large ones, like the Huntsman spider, which can have a leg span of up to 30 centimeters. Although their venom can cause discomfort, it is not harmful to humans, and they do not see us as prey since we don’t fit in their webs. If bitten, wash the area with soap and water, apply a cold compress, and take a pain reliever. If you experience an allergic reaction following a spider bite, seek medical help promptly.

The beauty of fish in Bali’s waters is captivating, but it’s safest to admire them from a distance. Their appearance can signal potential dangers: some fish have sharp spines on their fins that contain potent protein-based toxins. While this poison is not lethal, it can cause significant pain.

If you get pierced by a fish spine, follow these steps:

If you experience severe pain or other symptoms, seek medical attention promptly.

The stonefish is the most venomous fish in the world. Unlike the brightly coloured lionfish, the stonefish excels at camouflage, blending seamlessly with its surroundings. This makes it easy to accidentally step on, which can be extremely dangerous. Contact with a stonefish can be fatal. Its venom, like that of other venomous fish, is protein-based. If stung, immediately clean the wound, immerse it in hot water, and seek prompt medical attention.

This small yet deadly octopus is both stunningly beautiful and extremely dangerous. Measuring just 4-6 cm, it is commonly found in coral reefs around Bali and may sometimes appear in lagoons during low tide. While its vibrant colors are captivating, it’s crucial to admire this octopus from a distance and avoid touching or disturbing it. When threatened, it displays a dazzling array of colors as a warning. Despite its appearance, its venom is potent enough to kill 26 adults.

If someone is bitten, perform artificial ventilation until medical help arrives, as the venom causes paralysis. However, there's no need to be overly concerned about the sea, as there have been only 18 recorded fatalities worldwide from this creature. Typically, it will swim away at the first sign of danger.

Bali’s waters are home to a variety of shark species, including blacktip reef sharks, whitetip reef sharks, gray reef sharks, Balinese cat sharks, angel sharks, Bull sharks, Grey sharpnose sharks, and occasionally, the great white shark. Generally, sharks do not pose a threat to humans, as we are not part of their food chain. If you encounter a shark, remain calm and give it space. Shark diving in Bali is popular and considered safe, as these creatures do not see humans as prey. Since 1990, there have been only five recorded shark attacks in Bali, none of which were fatal.

In the unlikely event of a shark attack, playing dead won’t be effective. Instead, defend yourself with whatever you have—such as a surfboard, diving gear, fishing equipment, or even your fists. Instead, defend yourself using anything at hand—like a surfboard, diving gear, or even your fists. Quick, sudden movements may scare the shark, and if you must strike, aim for the eyes, nose, or gills, which are its most sensitive areas. Get to shore or a boat as soon as possible. If bitten, apply a tight bandage above the wound to control bleeding and seek immediate medical attention, regardless of the bite’s severity. It’s also helpful to wrap the injured person in a blanket to prevent heat loss.

When it comes to Bali's wildlife, the best advice is straightforward: always observe animals, fish, and insects from a safe distance, and avoid touching or disturbing them, no matter how cute or harmless they may seem. By following these guidelines, you're likely to enjoy only pleasant memories of your encounters with Bali’s fascinating wildlife.