Dangerous Animals in Hawaii: 7 Creatures to Definitely Avoid! 

Dangerous Animals in Hawaii

When you first think of Hawaii, chances are that the pictures in your head are of golden beaches, azure waters and happy hour Mai Tais. Not stinging jellyfish, biting spiders, and foot-long angry centipedes.

But don’t let the thought of deadly animals put you off too much, the truth is that there aren’t many animals or creatures in Hawaii that will seriously hurt you. Hawaii has no snakes (well, not technically), no crocodiles, no large cats and no bears. But, like every other place on Earth, Hawaii does have some dangerous creatures that you need to look out for.  

So, over the next few minutes, we’re going to look at some of Hawaii’s most dangerous animals, and some of their habits. And hopefully, we’ll be able to keep you a little bit safer as you explore the wonderful islands of Hawaii.

(Fun Fact: the official state bird of Hawaii is a goose! It’s the Nene Goose – pronounced “nay-nay” – and it’s officially the rarest goose in the world.)  

Are There Any Poisonous Animals in Hawaii?  

poison bottle

The short answer is no. The long answer is also no. But before we explain our answers, here’s a quick biology lesson (stay awake at the back!)

Poisonous or Venomous: What’s the Difference? 

Lots of creatures produce chemical toxins which are used to kill or incapacitate prey, or as a defence against attackers. Most of these toxins are harmless to most other species, including humans. A creature is known as venomous if it delivers this toxin as part of a venom, which is injected into another creature by a bite or a sting. If the toxin is only delivered on contact (or if you eat the flesh of an animal that produces a toxin) then the animal is said to be poisonous. 

So: toxins delivered by bite or sting are venomous, toxins delivered by touch or ingestion are poisonous. And the answer to the question is no, there are no poisonous animals in Hawaii. But there is one poisonous flower, which we’ll get to soon… 

Are There any Poisonous Venomous Animals in Hawaii?

What a well-worded question – how nice to see that you’ve been paying attention! The answer to this question is yes, there are definitely venomous animals in Hawaii. As we’ve said before, these animals are not looking to attack you – they’d rather just be left alone to get on with their lives. But sometimes, if threatened, they will attack – which could cause anything from a nasty rash to a worrying fever. And, in some rare cases, lack of proper medical treatment can prove fatal.  

So, with that being said, let’s take a look at some of the dangerous animals in Hawaii, and how to avoid making them angry!

The Giant Centipede (Scolopendra subspinipes)

Giant Centipede
The Giant Centipede can grow up to 12 inches in length

There are three types of centipede in Hawaii. Two of them are quite harmless but the other one – the biggest one – is a nasty piece of work.

The Giant Centipede (aka Jungle, Vietnamese and Chinese Red-Headed Centipede) can grow up to 12 inches in length, and tries to eat almost every living thing that isn’t longer than itself! This is a fast and aggressive centipede, which strikes instinctively at the slightest provocation. And they’re not shy of humans: in Hawaii, bites from centipedes account for 11% of bite victims every year.

The Giant Centipede doesn’t much like the heat, so they mainly go out at night to hunt for, well, just about anything – up to the size of mice and small lizards. During the day they like to sleep in moist and darkened areas, under logs or a pile of rocks. But they’re also happy to hide away in sleeping bags and duvets, which is why campers and backpackers are warned to be extra careful before settling down for the night.

 They also occasionally make a home under an indoor carpet, especially in areas where there’s a lot of moisture, such as near the bathroom.

Giant Centipede on a human hand
This guy is VERY brave! | Photo Credit: Arachnoboards

When a human is bitten, the centipede will cling to the skin and keep biting, so if you see one on someone’s skin, try to beat it off as soon as possible! The bite leaves two puncture wounds, and the infected area will start to hurt like a very powerful bee sting. The pain can be excruciating, and sometimes lasts for weeks. 

The infection can cause extreme swelling of the bitten area, but that can be swiftly treated by local hospitals who all have experience with centipede bites. In very rare cases, an allergic reaction to the toxin can cause complications, and there have been fatalities after a bite from a centipede. But, statistically, over 90% of bites heal with no complications and no lasting marks.

There’s a good chance that you’ll meet one of these angry millipede-wannabees whilst you’re in Hawaii, although the 10-12” ones aren’t that common. Just remember to give them a wide berth if you see one nearby, and you’ll be fine.

Similar to Centipedes

 Most caterpillars are fuzzy, cute little things, but there’s one in particular – the Stinging Nettle Caterpillar – that will really hurt if you even just brush against it. It’s covered with spiny hairs that get under your skin in a way similar to fibreglass. In addition, the spines release histamines that cause an intense burning and itching sensation. A very few people are allergic to the histamine toxin, and this can lead to breathing problems. The Stinging Nettle Caterpillar is also a fearsome pest, that causes significant damage to a wide range of agricultural, landscape, and endemic vegetation.  

Conus: the Deadly Snail (Conidae)

A Cone Snail
A cone snail inside his shell | Photo Credit: ecomagazine.com

Although this might sound like the title of a terrible prequel to Conan the Barbarian, it’s a fact that some of the sea snails in Hawaii have a toxin that can be deadly to humans. These are the Cone Snails: extremely venomous predatory sea snails that are found in tropical seas, feeding on marine worms and small fish.

Shell of the Banded Marble Cone Snail
Shell of the Banded Marble Cone Snail | Photo Credit: gastropods.com

The 34 species of Hawaiian cone snails live in the most beautiful of shells, with intricate patterns and amazing colour schemes. This makes them popular with collectors, who walk the beaches looking for shells to add to their collection. But this is a mistake, because picking up the wrong shell can have serious consequences. If there’s a snail inside, it will feel threatened and it will strike!

The three that are especially dangerous are the Textile (Conus textile), Striated (Conus striatus oahuensis). and Banded Marble cone snails (Conus bandanus). A few microliters of their toxin is powerful enough to kill 10 people, and they have a nasty hypodermic harpoon delivery system that can strike in milliseconds. 

Shell of the Textile Cone Snail
Shell of the Textile Cone Snail | Photo Credit: gastropods.com

In Hawaiian, these snails are called pūpū pōniuniu which translates to ‘dizzy shell’. But this is nothing to do with the design on the shell – it’s because settlers in Hawaii knew that touching these shells would make you go dizzy. Nowadays, we’d refer to this as going into anaphylactic shock.

Because all cone snails are venomous and capable of stinging humans, live ones should never be handled.

 

Shell of the Striated Cone Snail
Shell of the Striated Cone Snail | Photo Credit: gastropods.com

For humans, the sting from the smaller cone snails is no worse than a bee sting, but a sting from the larger tropical cones can be unbearable and extremely serious. Severe cases can lead to muscular paralysis, blindness and respiratory problems – and even death. A small number of deaths have actually been recorded, although none of them were based in Hawaii. 

But it’s not all bad news! You’re very unlikely to ever encounter a cone snail unless you’re actively looking for their shells, and even then only the shells with live snails inside can harm you. And studies of the strong venom show that it could well be a source of some important medical resources, especially as a painkiller. Now, that’s ironic!

Red Velvet Ant, aka ‘Cow Killer’ (Dasymutilla occidentalis)

The Red Velvet Ant
The Red Velvet Ant | Photo Credit: Alchetron, the free social encyclopedia

This is one of the smallest creatures on our list, but it’s one you’ll want to avoid. Especially the one without the wings(!) 

The Red Velvet Ant is actually a wasp, not an ant, and it grows up to an inch long. The male has wings, as you can see from the picture above, but the female is flightless. Of the 30,000+ species of wasps in the world, 7,000 are part of the ‘velvet ant’ group, all with a dense pile of fuzzy hair on their backs – hence the name. Their lurid colouring and broad, striped pattern serve as danger signals: this creature stings!

In fact, only the females sting and – being wingless – they’re confined to the ground. So although the males can definitely be a pest, they’re pretty-much harmless. The female’s sting, on the other hand, is said to be “strong enough to kill a cow”, which is why they’re known as ‘cow killers’ (and not because they actually kill and eat cows).

You’ll normally find the females scurrying around in sandy areas, although sometimes they’ll head inside if they sense prey. The male wasps are usually found on flowers, or flying low to the ground looking for potentially friendly females.

Red Velvet Ant
Photo Credit: washingtonpost.com

Although their nickname is quite unnerving, the Red Velvet ant is not aggressive and will only sting as a last defence. A sting to a human can be extremely painful, but usually fades after about 30 minutes. Also, the actual toxicity of their venom is quite low, so further medical problems are unlikely.

But these wasps have a dark side: when it comes to giving birth, the female’s character becomes quite macabre. First, she finds a ground-level nesting chamber of bees or wasps, then she tunnels in. She finds the unhatched larvae inside, and lays her own eggs right on top of the larvae. When her eggs hatch, the young ants eat their defenceless hosts, and finally use the empty pupal casings to spin their own cocoons. What a horrible start to life!

Tiger Shark (Galeocerdo cuvier)  

Tiger Shark
Tiger Shark | Photo Credit: DinoAnimals.com

Sharks attacks in Hawaii happen at the rate of 2-3 per year, which is one of the lowest rates in the world. Since records began in 1828, there have only been 11 shark fatalities recorded, mostly around the island of Maui. 

So, although sharks can be dangerous, there’s more chance of you being hurt in a freak deckchair accident than being mauled by a shark.

The most dangerous of all Hawaii’s sharks is the Tiger Shark, easily recognised by its blunt snout and the vertical banding on its sides. White sharks are also very dangerous, but they only make rare trips to the Hawaiian Islands. Other common visitors include the Whitetip Reef, the Sandbar and the Scalloped Hammerhead.

Sharks might look frightening, and have a fierce reputation, but it’s widely accepted that sharks are more afraid of us than we are of them. Sharks are survivors and they are very wary of coming too close to humans: too many times those humans are there just to kill the shark, harvesting it for the medically-valuable oil produced by its liver. So they tend to stay away from us.

Diver sitting on sea bed with Tiger Shark
Diver gets incredibly close to a Tiger Shark | Photo Credit: Steve Hinczynski, Media Drum World

The Florida Program for Shark Research is run by Gavin Naylor, who tells us “[sharks] generally just ignore people. I think if people knew how frequently they were in water with sharks, they would probably be surprised.” 

There is some advice that suggests punching a shark in the head (or the eye) will stop them from attacking you. Marine biologists suggest that this is probably true, but most shark attacks come from below and are so quick that there’s not much time to react.  But unless you’re a regular surfer, or you’ve signed up for a ‘swim with the sharks’ experience, you are very unlikely to ever see a shark, let alone be attacked.

Sharks are apex predators that help to balance ecosystems through their diet, picking off the weakest and slowest fish and helping to strengthen the gene pool of prey species. Scientists consider them to be a ‘keystone species’, and warn that marine ecosystems would collapse if sharks weren’t there to play their part.

Yellow-Bellied Sea Snake (Hydrophis platurus) 

Yellow-Bellied Sea Snake
The Yellow-Bellied Sea Snake | Photo Credit: The Ocean Project on Twitter

Hawaii used to be able to boast that the islands had no snakes, because there are strict laws and programs in place to keep them snake-free. However, one of the world’s most prolific sea snakes has managed to make it to Hawaii, and it’s quite venomous.

As its name suggests, the snake has a bicolour pattern with a brown back and a very obvious yellow underbelly. Hampered by small ventral scales common to all sea snakes, the yellow belly moves very poorly on land and prefers to spend most of its life in the water. They can sometimes be seen in large groups of thousands, drifting on the surface and using the oceanic drift currents to wait for prey. 

Like all other sea snakes, the Yellow-Bellied Sea Snake carries a highly potent neurotoxic venom, which can prove very harmful to humans. Luckily, sightings of the yellow belly are rare and bites are even less common. No fatal incidents have ever been reported. 

The Brahminy Blind Snake: Hawaii’s ‘Other’ Snake

Even though Hawaii has an official no-snake policy, there was one tiny snake that slipped through the cracks. 

The Brahminy blind snake
The tiny Brahminy blind snake | Photo Credit: Quora

Sometimes known as the Flowerpot Snake because they’re commonly found living in one, the Brahminy blind snakes (Indotyphlops braminus) are the smallest known snake species in the world, measuring less than 10cm.

They are fossorial, meaning they burrow under the earth to make a home, and that’s why they’re often confused with earthworms. Their tiny eyes, just noticeable in the picture above, are completely covered by translucent scales, which means these pocket-sized snakes are almost completely blind. 

Black Widow Spider (Latrodectus mactans)

The Hawaiian Black Widow Spider
The Hawaiian Black Widow Spider

Hawaii has many gruesome-looking spiders but, out of all of them, the most feared is the Black Widow. There are about 40 different species of black widow throughout the world, and all of them go through that gruesome wedding night, where the female notoriously kills the male after mating. 

The Black Widow has taken up residence in almost every country of the world, including Hawaii and other parts of the US. The female widows spin their three-dimensional webs in corners of fields and gardens. They hardly ever venture away from their web, preferring to patiently wait there for their next meal. 

The distinctive red hourglass shape on the female is a well-known warning sign in nature, and with good reason — female black widows are highly toxic. The male isn’t really worthy of comment: he doesn’t spin a web, he’s half the size of the female, and he carries no venom. (And anyway, most males don’t make it past their wedding night!)

According to National Geographic, black widow venom is up to 15 times stronger than the venom from a rattlesnake and carries a neurotoxin — latrotoxin — which can cause severe muscle pain. Further symptoms may include abdominal cramps, muscle rigidity and an elevated heart rate. In very few cases, the bite can prove fatal.

 Luckily, like most creatures, the Black Widow spider will only bite a human if disturbed, and only the bite of the female poses any sort of threat.  Contrary to popular belief, most widow bite victims do not suffer any serious damage, and no actual fatalities have been reported since 1983.

Hawaii is also home to the Brown Widow spider, which although smaller has a venom twice as potent as the Black Widow. However, being smaller, the brown widows don’t inject as much venom and are more timid, so less likely to defend their web.

Want More Spiders……..?

The Brown Recluse Spider (Loxosceles reclusa)  

Brown Recluse spider
Brown Recluse spider | Photo Credit: P Naskrecki @ naturepl.com

The Brown Recluse (aka Brown Violin or Fiddle-Back), is venomous, and can usually be found hiding in sheds, closets, garages, cellars, and other places that are dry and generally undisturbed. It particularly likes to live in old cardboard boxes. It’s not particularly aggressive, and if threatened it will usually just run away, but it will bite if provoked. Its bite is potentially deadly, inflicting a hemotoxin which can cause necrosis. (Fast Fun Fact: Brown recluse spiders only have six eyes, not eight!)

The Huntsman Spider, aka Hawaiian Cane Spider (Heteropoda venatoria)

The Cane (Huntsman) Spider
The Hawaiian Cane Spider

Although this spider looks terrifying, it’s venom is not harmful to humans. The cane spider (as they’re known in Hawaii) is about the size of a human hand, and it’s very fast! They don’t build webs, preferring to hide in crevices where they can rest undisturbed. Huntsmen can be aggressive, and the female will attack if she feels her young are threatened.

Kauaʻi Cave Wolf Spider (Adelocosa anops)

Kauai Cave Wolf Spider
The blind Kauai Cave Wolf Spider | Photo Credit: wired.co.uk

The Kauaʻi cave wolf spider, also known to local residents as the ‘blind spider’, is only known to exist in a few particular caves on Kauaʻi Island. It’s definitely part of the feared wolf spider family, but it’s only 10mm across and, unfortunately, totally blind, with no eyes at all.

Box Jellyfish (Carybdea) 

The Hawaiian Box Jellyfish
The Hawaiian Box Jellyfish (Carybdea alata) | Photo Credit: pinterest.com.

At least three species are known in Hawaiian waters. The largest, and the most dangerous, is the Hawaiian, or sometimes Winged, Box Jellyfish (Carybdea alata). The other two are the Jimble Box Jellyfish (Carybdea rastoni) and Carybdea Sivickisi, which is a tiny jellyfish with a bell diameter of about 2 mm and a length of only 7 mm. It’s also too small to get a real name, so we have to use the Latin version.  

Here’s the bad news: box jellyfish are extremely venomous. The undisputed king of the ‘box jellies’ is the Australian Box Jellyfish (Chironex fleckeri), which marine biologists consider to be the most venomous marine animal. Ever.  

Box jellies are highly advanced among jellyfish. For one thing, they can actually swim – at up to 4 knots – whereas most jellyfish species just float with the currents, with no control over their own direction. Box jellyfish can also see. They have clusters of eyes on each side of their ‘head’ – some of which are surprisingly sophisticated and can react to changes in light. Some researchers believe that their speed and vision is proof that box jellyfish actively hunt their prey, which is mainly small fish and shrimp. 

The Box Jellyfish Carybdea rastoni
Box Jellyfish (Carybdea rastoni) | Photo Credit: Ocean Treasures Memorial Library

Each of the box jellyfish’s tentacles is covered by up to 5,000 stinging cells, called nematocysts, which are barbed so that they can penetrate the skin easily but are difficult to pull out. The venom injection is immediate, and is enough to kill small prey instantly. With human victims, the toxins can attack skin cells, the heart, and the central nervous system. The pain can be so overwhelming that some people have been known to go into shock and drown before ever reaching the shore.

But thankfully, the box jellies you’ll meet in Hawaii are not deadly. The pain, if you get stung, will certainly be excruciating but it usually fades within the first hour, and disappears completely within 3-12 hours. Unfortunately, a run-in with a box jelly may well result in scarring, which can sometimes take time to fade.

Lifeguards in Hawaii are extra vigilant when it comes to jellyfish, and beaches will be closed if jellyfish are sighted heading towards the shore. Actually most beaches have plenty of time to prepare, as jellyfish follow a very predictable timetable.

Box Jellyfish Copula sivickisi
The tiny Box Jellyfish Copula sivickisi | Photo Credit: NZ Geographic

For about two days after the full moon, the jellyfish will mate in deep waters beyond the reefs. During the mating ritual, the jellyfish will be blown steadily towards the shore. A lot will get caught out by the receding high tides, leaving them trapped very close to the coastline. The University of Hawaii’s Waikiki Aquarium maintains a box jellyfish calendar, which shows the dates for influxes of jellyfish. If the calendar says ‘jellyfish’, locals stay out of the water.

If you get stung by a box jellyfish, do not scrape at the tentacles – only 1-10% of the venom is injected when the stinging cells are first triggered, and any sharp movements will force the rest to be delivered. According to research at the University of Hawai’i at Mānoa, the most effective treatment is to rinse the area with vinegar, or pluck the tentacles out individually – and very slowly – with tweezers. Applying a heat pad once you’ve got dry also helps to decrease the venom activity.

Lastly, we’d warn you to stay away from all jellyfish, even the dead ones – their tentacles can continue to deliver a sting long after the jellyfish has died.

Similar to the Box Jellyfish

Less dangerous, but just as well-known, is the Portuguese Man-O-War (Physalia physalis). On the windward side of all Hawaii’s islands, you’ll find quite a few of these creatures floating aimlessly through the water, blown along by the gas-filled bubble in their heads which keeps them afloat. Their tentacles are usually between 33 and 160 feet in length, and venom gets injected by way of tiny barbs -in a similar way to the box jelly. The stings will almost certainly cause intense pain, but prompt treatment by a doctor will prevent any further complications.

Dangerous Animals in Hawaii: A Final Word

So that brings us nearly to the end of our round-up of dangerous animals in Hawaii. But we did promise one genuinely poison Hawaiian species, and so here it is: 

Angels Trumpet, aka Trumpet of Death (Brugmansia)

 Angel's Trumpet - The 'Hawaiian Double White' variety
Angel’s Trumpet – The ‘Hawaiian Double White’ variety | Photo Credit: GardenForPleasure

The Angel’s Trumpet is, without doubt, a beautiful plant. But every part of it is toxic, and even just touching it can prove fatal.

The pretty bugle-shaped flowers of Angel’s Trumpet make this plant a delightful addition to any garden, especially the Hawaiian variety known as the ‘double white’ because of its unique horn-within-a-horn-shaped flower. But this is one of the most toxic ornamental plants you can find and should never be touched by hand, unless it’s through thick gardener’s gloves. These plants contain tropane alkaloids similar to those found in the infamous Deadly Nightshade.

Every part of the plant is very poisonous from the leaves and flowers to the seeds and roots. The toxin can be released by just touching or brushing up against the plant, and is delivered by absorption through open membranes, which include the nose, the mouth and the eyes. In this sense the plant is not venomous but truly poisonous, as the toxin is not injected in any way.

Angel's Trumpet - the Cherub variety, noted for its salmon-pink flowers
Angel’s Trumpet – the ‘Cherub’ variety, noted for its salmon-pink flowers

For example, if a gardener without gloves was working on these plants and then rubbed his eyes, he would contaminate himself. Similarly, if that gardener then made you a plate of food without first washing his hands –  and you ate it – you would likely suffer from food poisoning, due to the flower toxin that had made its way to the food surface.

 In ancient Peru, when a Lord died, angel’s trumpet seeds would be mixed with maize beer and tobacco leaves to form a potent drug. This drug would then be given to the Lord’s wives and slaves, causing them to start having strong hallucinations. In their drug-induced state, they would be taken to the grave of their dead Lord and buried alive.

The initial symptoms of Angel’s Trumpet poisoning include dilated pupils, muscle weakness, dryness of the mouth, a rapid pulse, sudden fever and hallucinations. If left untreated seizures, paralysis and respiratory failure may follow which can lead to a coma state or even death.

However, if looked after properly, these flowers will continue to look beautiful year after year. Just, whatever you do, don’t ever touch them!

A Final, FINAL Word

We hope you enjoyed our look at some of the amazing yet deadly creatures of Hawaii. It’s true that a lot of these creatures carry enough toxins to seriously hurt the average traveller, but it’s important to remember that the venoms and poisons were not invented specifically to harm humans. They were designed to stun or kill natural prey, allowing the host creatures to eat and survive. 

Mankind is seen by nature as an apex predator at the top of the food chain. This is why most creatures will only attack a human as a last resort, meaning that if you leave them alone, they’ll generally leave you alone.

When we take pictures of cute creatures or move in close to view some scary spiders, we are entering their world. As long as we respect their rules, we’ll be fine.

If you’ve enjoyed this post about Hawaii, you might be interested in looking at our guide to Hiking in Hawaii. Or, if creepy-crawlies are more your thing, then check out some of the spiders that live in Thailand!

BTW: We love hearing from all of you that read our posts. So if you want to ask us a question about travel, or you just want a general chat, please get in touch. We love to help, and we love to talk!