Mexico has one of the most diverse natural habitats in the world. Its flora and fauna are the fourth most varied and diverse on the planet, after those of Brazil, Colombia, and Thailand. To accompany this diversity, Mexico is also home to a colossal variety of insects, arachnids, snakes and other wild creatures.
Most, with the exception of mosquitoes, will leave humans alone and more often tend to scarper from you unless they feel threatened. However, when you’re traveling in Mexico —and particularly in rural areas— you may come into some contact with one or more of these common species which dwell locally.
Here is a list of the most commonly-found critters, with tips about dealing with them:
Mosquitoes proliferate in Mexico during the rainy season (May to October) across Mexico’s coastal areas, as well as inland in the highland central and southern regions; although they maintain a near-continual presence in the humid jungle regions of southern Mexico. Insect repellent is vital if you are trekking outdoors in jungle areas including, for example, some of the archaeology parks situated in jungles. At night, hotels which have open-air windows may provide mosquito nets over the beds. Read our related article about dealing with mosquitoes in Mexico for detailed tips and guidance.
Most snakes keep away from humans, although if you are trekking outdoors, caving, or driving across the open countryside, you may see some snakes in Mexico. If you are unfortunate enough to be bitten by one, make a concerted effort to identify it (take a picture of it if you can, or at least be able to describe it in detail) as this will help a doctor to administer an appropriate antidote. A rule of thumb about snakes’ toxicity to humans is that snakes with arrow-shaped heads are usually quite venomous to humans, and so you should be particularly mindful of these.
Mexico’s scorpions are not as deadly as those which are found in the Middle East. There are three colors of scorpion in Mexico: black, brown, and light yellow. They can give you a very painful sting, but are rarely life-threatening unless you are very young, very old, infirm, or allergic to the venom. The ones locals tend to watch out for are the light yellow ones; they are colloquially referred to as alacranes gueros. (Guero in Mexican Spanish means “light-skinned.”) If you are stung by a scorpion (any color) seek help from a local doctor or local health clinic where you can be administered with an antidote. Like snakes, most scorpions try to keep away from humans; however, being nocturnal creatures, they have a tendency to crawl into shoes and clothes overnight, so if you are in or near a (semi)rural setting, take the precaution of shaking out any clothes and shoes you may have left out before you step into them the next morning.
Mexico has a huge variety of spiders; some are venomous and some not. Tarantulas are very common here —and look scary— but are mostly benign to humans. There are three venomous spiders in Mexico which you should be mindful of: The ‘Black Widow’, the Brown Recluse (also known as a ‘Fiddle-back’ due the shape of its body), and the Hobo spider. Read our related article about spiders to be mindful of in Mexico for additional guidance.
Every ocean world-wide is home to some species of jellyfish (cold and warm waters), and this includes Mexico’s ocean waters on the Pacific and Gulf coasts as well as in the Caribbean waters off the Yucatán peninsula. Jellyfish look graceful in the water; when they are washed-up onto the beach they look like jelly blobs: beware, as wet jellies on the beach can sting. They can range in size from an inch to a couple of hundred feet in length. Less than half of all jellyfish harbor a poison which is dangerous to humans. Notwithstanding this, the stings are usually extremely painful. Getting out of the water is a priority followed by some immediate medical help, which may include the administration of an antidote in severe cases. Some, but not all, popular beaches in Mexico will post signs about the presence of jellyfish—in Spanish they are called medusas. If you are stung, the advice is to rub white vinegar or isopropyl alcohol into the affected area: washing the area with water will make it worse. The waters of the Gulf of Mexico are home to three jellies which can be dangerous to humans: Lion’s Mane, Portuguese Man-of-War, and the Sea Nettle.
You can learn more about health matters, including vaccinations and common health ailments, on the Mexperience guide Travel Health in Mexico.
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