Processionary caterpillars
These fuzzy characters top the list because they can be extremely harmful, even fatal, to dogs, cats, and other small animals. Orange and brown in colour, these nasty characters are easy to recognise because, as their name suggests, they walk in single-file processions, head to tail. They are also hairy in appearance, although those ‘hairs’ act like tiny harpoons, which is what makes them dangerous.
As we said, the main risk is to your pets, and it can even be fatal to dogs, cats, and other small animals. If spring temperatures are higher than average, the caterpillars can appear in especially high numbers. Their nests are silver-coloured and are found especially in areas with pine trees. So, keep an eye out for them, but whatever you do, do not touch them or let your pet near them!
Processionary caterpillars aren’t the smartest, though. Well over a century ago, a French naturalist called Jean-Henri Fabre arranged a group of these caterpillars into a full circle around the bottom of a flowerpot to test their urge to follow one another in single file, head-to-tail. They followed each other in a circle around the flowerpot for seven days! We’re not sure whether, after the seven days, Jean-Henri couldn’t take it anymore and broke up the line, or whether the caterpillars finally copped on. We reckon it was probably J-H, and that the caterpillars would still be going today if he hadn’t stopped them!
Sandfly
Like the processionary caterpillar, most bugs pose more of a danger to your pet than to yourself. From May to October, the not very aptly named sandfly (which lives in wooded and garden areas) can be a danger to your dog, as it transmits Leishmaniasis, a disease that has been endemic in dogs for centuries but is extremely rare in humans. Prevention is definitely better than a cure in this case, as there is no cure at present. Fitting your pet with a preventive collar during the season is the best strategy.
Tick
The tick is another critter prevalent throughout Spain that can transmit incurable diseases to your pet, particularly in spring and autumn. Again, a preventive collar can help in this case and will also help with fleas. Ticks can also pose a risk to humans, as they can spread bacteria that cause Lyme Disease, though this is uncommon.
There are plenty of other insects that can sting, such as wasps and hornets, but for the most part (unless you have an allergy), these are more of a nuisance than a danger. If you do get stung, try to remove the sting right away if possible, but do not use tweezers! If the sting contains venom, using tweezers may inject more venom into the skin, increasing irritation. In the case of an allergic reaction, a person may begin to go into anaphylactic shock, so do not hesitate – call an ambulance! Better safe than sorry.
Asian wasp/hornet
Scientifically named Vespa Velutina, these insects are more concerning than ‘regular’ wasps. Although not yet common in Catalunya, they have been sighted, and there are fears that this species is gradually spreading across the Iberian Peninsula. They first arrived in Spain in Galicia, where they caused one fatality, along with another in Asturias, and appear to be spreading in every direction.
Originally from Southeast Asia, they have invaded many regions worldwide. Although they are not aggressive and attack only en masse when their nest is threatened, they have been declared pests in many countries. Although they could be classified as somewhat dangerous, the main peril is not to humans but rather to bees.
The eastern honey bee, which it preys upon in its native habitat in Asia, has evolved a strategy to avoid it (too long to go into here), but our European western honey bee has no such defence. If you think you recognise one (or some) of these hornets, try to take a photo if it’s safe to do so, but do not approach in case there’s a nest.
If you believe you have spotted one, it’s best to keep your distance and avoid approaching any possible nest. A photo from a safe distance can help with identification, after which local pest control services can advise on the next steps.
Snakes
There are 13 species of snake native to Spain, but only five are venomous, and two of those five are not even found in Catalunya. Of the other three, either they do their best to live as far away from humans as is “serpently” possible, or their venom is not strong enough to make them dangerous to most humans. In fact, more people die from wasp and bee stings than snakebites. The wisest course of action if you come across a snake of any kind is to give it a wide berth, both for your own sake as well as for the snake’s. Just leave ‘em alone!!
If you are unfortunate enough to be bitten by a snake in Catalunya, try to snap a photo for identification, or at least get a good look, stay as calm as possible, and seek medical assistance immediately.
Scorpions
Not much to worry about here… Although there are some species of both that can bite or sting, they are not particularly dangerous, except for people with certain allergies. If you do suffer from such an allergy, it’s probably a good idea to wear ankle boots if out camping or hiking in the woods – and before putting on your footwear in the morning, it’s another great idea to give it a good shake in case of any uninvited creepy crawlies taking up temporary residence within overnight.
Shark!!!
Yes, there are sharks in the Mediterranean – almost 50 species of them altogether! A 2.5-metre-long bluntnose sixgill shark, often simply referred to as the cow shark (not dangerous to humans), was washed up on Es Monestri beach in Sant Antoni de Calonge in February 2023. A 5m Great White Shark was even spotted off the coast of Mallorca in 2018 – the first confirmed sighting in Spanish waters for over 30 years.
The sharks have always been here in the Med, and considering the huge numbers of people that live or holiday on Mediterranean shores, it’s remarkable how rare shark encounters are. Most species of shark in the Mediterranean prefer open water and feed on tuna (there aren’t many seals!) and so rarely come into contact with humans. Unfortunately, shark numbers have been declining, and this has a not-so-positive consequence for swimmers: more jellyfish!
Jellyfish
These strange creatures can be difficult to see in the water, and contact with them can produce a very unpleasant sting. Fortunately, the stings from jellyfish in Mediterranean waters are rarely life-threatening unless (you guessed it) you have an allergy. The Australian Box Jellyfish – now that would be a different story. Those guys are considered amongst the most dangerous creatures on the planet, but thankfully, they live up to their name and stick to northern Australia and Indonesia.
If you do get stung, do not rinse the affected area with fresh water, any form of alcohol, or urine, as this can re-stimulate the stingers. Vinegar is supposed to be the best immediate treatment (if you happen to have it with you at the beach!), and any clinging tentacles are best removed with tweezers or something “rough” like a towel. Even if you see a dead jellyfish washed up on a beach, don’t touch it, as the tentacles can still sting after death. We need more sharks!
Portuguese Man O’ War
Though the Portuguese Man O’ War is often mistaken for a jellyfish, it is not actually a jellyfish. These creatures sometimes drift into Catalan waters and possess long, venomous tentacles that can deliver painful stings, sometimes dangerous. If you spot one on the beach, it’s best to keep your distance.
Spiders
There are a few species of spiders that are venomous but not really dangerous, as none carry enough venom to worry humans unless you happen to have the wrong type of allergy.
Latrodectus Tredecimguttatus
Scary name! This spider is commonly referred to as the European or Mediterranean Black Widow, and as its name suggests, the female is probably far more dangerous to her mate than to any of us. In fact, only the female is capable of biting a human. Although such a bite is painful, it is not common and is rarely fatal to humans; it can, however, be dangerous to the very young, the elderly, or those with weak hearts. These spiders are found throughout the Mediterranean and western Asia.
Violin Spider
Its Latin name is Loxosceles Rufescens, and in Spanish, it’s called the araña violín, or ‘violin spider’, due to the markings on its back. Also known as the Mediterranean Recluse Spider, it is native to the Mediterranean region. It is just one of a very long list of ‘recluse spiders’, most of which are from Africa and the Americas, both South and North. Their name is apt as they like to look for dark, hidden corners to weave their webs. Despite millennia of cohabiting the Med with humans, there has only been one fatality suspected (though unconfirmed) of having been caused by a violin spider bite.
Lycosa Tarantula
This one sounds scarier than it is – and there’s a story behind that! This spider is native to southern Europe and is especially common in Italy, and more specifically around the city of Taranto, which gave it its name: tarantula. When Europeans arrived in the Americas, they encountered spiders far bigger than any they had ever seen at home, and they called them tarantulas after the most enormous spider they had known up to then: the Lycosa Tarantula.
Since then, the American giants hogged the new name all for themselves, and the European species was ‘downgraded’ to become known as the (tarantula) wolf spider, or araña lobo in Spanish. They have very good eyesight and tend to flee when any large animals, like humans, approach. Their venom is also weak, and if you were to get bitten, it would feel no worse than a wasp sting.
Spanish Funnel-Web Spider
If you have ever been to Australia you’ve probably heard about the funnel-web spider from Down Under that has a vicious bite and has killed humans in the past (though not for a long time, thanks to improved first aid). Do not be alarmed! The Spanish version, although large and a bit fearsome-looking, has a venom that is not dangerous to humans. We only include it to let you know there’s nothing to worry about, despite its shared name with its Aussie cousin! (What is it with Australia and dangerous animals anyway?)
Stinkbugs
Yep, you read correctly: stinkbugs! This is another invader from Asia, known scientifically as Halyomorpha Halys or the ‘brown marmorated stink bug’, and it has recently been spotted in Girona. It doesn’t bite or sting, it’s not poisonous, and it is not in any way dangerous to people, but we included it in this blog because it can cause significant damage to crops and gardens. In winter, they tend to hibernate in people’s houses, hiding in any crevice they can fit into to wait for the spring.
Sometimes, however, the warmth of the house will cause them to become active again too soon, and they make nuisances of themselves flying around lights and not wanting to go outside – and then when they do go outside, they start eating your garden. It’s not a good idea to try to stamp on them or even move them on, as disturbing them will cause them to release their horrible defensive odour. They didn’t get the name stinkbug for nothing!
Wild Boars
Wild boars can be assertive animals, particularly when they feel threatened or are protecting their young. They are also responsible for many road accidents, so extra caution is advised when driving at night in rural areas. Collisions with wild boar are unfortunately becoming more common as their population increases, and they are dangerous for everyone involved, the animal, the driver and the vehicle alike.
And last, but by no means least: Mosquitoes
Mosquitos, which literally means ‘little flies’ in Castellano (mosquits in Catalan), have been around for over 30 million years, and they are a nuisance rather than dangerous – at least in this part of the world. (Malaria was eradicated from Spain well over a half-century ago.)
While most people will never come across most of the ‘dangerous’ creatures mentioned above, we are all only too familiar with the mosquito and its irritating bite. It’s actually only the female that bites, using a sharp ‘proboscis’ (from Greek ‘pro’ (before/forward) and ‘bosko’ (to feed), and her saliva, which contains an anticoagulant protein to prevent your blood from clotting. Once she has had her fill of your blood and has gone, some of her saliva remains in the skin, causing itching and provoking a response from your immune system, which causes the red bump that continues itching until your immune cells break down the saliva protein.
There are various theories as to what attracts or repels mosquitoes. Some argue that certain blood types attract them, while others claim that they bite everyone and anyone, but that some people have a far milder reaction than others. It is more generally agreed that mosquitoes do seem to like perfumes and scented deodorants, while the smell of human sweat attracts them far less, so it’s best to stay smelly! Some people believe they like blood with alcohol, while others insist that drinking alcohol – especially gin + tonic – helps repel them. (We know which of those two theories we prefer!)
What is known for sure is that they are attracted by stagnant water (where they also reproduce) and are more likely to bite people wearing dark colours. Citronella candles may help keep mosquitoes away outdoors if there isn’t much of a breeze, although their range is limited. Indoors, try cutting a lemon in half, inserting a clove into each half, and letting them dry. It repels mozzies and also smells lovely, but again, it only works over a short range.
Wearing long sleeves and trousers at dusk, when mozzies are most active, hanging mozzie nets, or using fans to keep them away (they’re not strong flyers) are all logical and effective solutions, but not always practical. Mozzie-repellent sprays containing DEET or Picaridin work very well but might not suit everyone’s skin. DEET, in particular, can cause irritation to some people and has even been known to damage plastics and synthetic materials.
Picaridin hasn’t been around as long and isn’t as well-known, but it is as, if not more, effective than DEET and isn’t in any way corrosive. Ask your local pharmacy. You can also try synthesised oils made from eucalyptus, lavender, tea tree or citronella, which are more natural, although they tend not to last as long as repellents.
If you do get bitten, try applying lip balm, cool aloe vera gel or essential lavender oils to the affected area; the latter having the added bonus of also being a repellent. If you have none of those to hand, then rub a little of your own saliva on the bite or press the back of a hot spoon onto it to relieve the itching.
Finally, there’s a ‘mosquito forecast’ website you can consult to find out what level of mosquito nuisance your area is likely to experience in the coming days.
Despite Spain’s diverse wildlife, truly dangerous encounters are rare. Most animals avoid humans altogether, or pose a risk only in very specific situations. Whether you’re hiking in the mountains, walking through forests or swimming along the coast, a little awareness and respect for local wildlife goes a long way.