Idiots Guide: 12 Most Harmful Insects on Earth

If insects were a political party it would come as no surprise that their ‘likeability’ rating would be consistently circling the drain. The fact of the matter is that outside of entomologists, nobody likes bugs. In fact most people, myself included, absolutely despise them. Their chronic insistent annoyance aside, they can also be quite deadly. Certain bugs are responsible for the deaths of tens of millions of people world-wide each year. The main reason for this is that they can carry infectious disease from one human being to another. In fact, the greatest human health catastrophe in history, the bubonic plague epidemic, has it’s origins rooted in infected fleas that rodents carried in their fur. This sinister and lurid infestation spread all across Europe between the years of 1346 to 1353. Rat fleas were directly and/or indirectly responsible for the deaths of some 25 million human beings. In relation to size bugs can carry serious, deadly weight. Idiots Guide presents a list of some of the most dangerous bugs, particularly in terms of disease, the world has ever known. Revulsion completely expected. Bug repellent strongly advised.

deadly bugs cover

Let the countdown begin…

#12.  Bot Fly

Human Bot Flies

The ubiquitous bot flies are also known as ‘warble flies’, ‘heel flies’, and ‘gadflies’ among other lesser known names. Their larvae grow internally as parasites with various species known to grow inside the flesh and/or gut of their host. Gnarly.  The human bot fly routinely parasitizes humans which causes a disease called ‘myiasis’ which is a parasitic maggot infestation under the skin, inside the body. Nothing good to see here.

#11.   Tsetse Fly

Tsetse Fly

Tsetse flies are also known as ‘tik-tik flies’. They are unusually robust biting flies that terrorize the Sahara and Kalahari deserts of Africa. They are ruthless blood-suckers who feed on the blood of most mammals, humans included. Their feeding activity comes with the extremely unfortunate caveat of causing ‘Human Sleeping Sickness’ a disease which, when left untreated, causes the deaths of up to 500,00 human beings world-wide each year. The mortality rate is close to 100% in local villages who don’t have adequate medical resources. The tsetse fly is solely responsible for this parasitic disease.

#10.   Bed Bug

Bed Bugs

Most people either have 1st hand knowledge or know someone who knows someone who has 1st hand knowledge of the sinister ‘Bed Bug’ or ‘Cimex lectularius’ for the scientific minded. These bugs are nasty little parasites that feed themselves exclusively on the warm blood of humans. Just like ‘Vampires’. They have been blamed for a variety of illnesses including ‘Leprosy’, ‘Q-Fever’,’Oriental Sores’ and ‘Brucellosis’. None of them are any fun whatsoever. The location of their insertion bites can lead to serious infection, especially in children, the elderly and people with suppressed immune systems. Numerous bites can result in allergic reactions. Bed bugs transmit a parasite called ‘Trypanosoma Cruzi’ that causes ‘Chagas Disease’ which is one of the most deadly diseases in North and South America. These little bastards cause serious problems for households who have been invaded. Not the least of which is the abject emotional creepiness of having bloodsuckers living in your mattress. Simply awful.

#9.   Flea(s) / All Species Of…

Rat Fleas

Fleas are disgusting bloodsucking insects that support their existence by leeching off of the warm blood of mammals and to a lesser degree, birds. Using a sinister process called ‘Hematophagy’ these external parasites use their specially adapted mouthparts to clandestinely pierce their victims skin and suck out their blood. The fleas that exist on cats and dogs are the bastards that affect humans with the greatest frequency. However, rat fleas can cause the most devastation. A flea bite causes painfully severe itching, skin infections and spread serious diseases including ‘Typhus’, ‘Cat Scratch Fever’ and the incendiary ‘Black Plague’ (Bubonic) which is a deadly infection caused by a bacteria called ‘Yersinia Pestis’.  This plague caused the deaths of approximately 25 million human beings over the course of 7 years. The numbers are staggering, all initiated from this dirty little bloodsucking bug.

#8.  Parasitic Worm

Parasitic Worms

With diabolical efficiency, Parasitic Roundworms make their way from moist earth soil into the human intestinal tract where they cause a litany of serious health problems. It is posited that a person inadvertently picks them up with their hands and they get transferred to the mouth. They are also contracted by the larvae which can enter the human body directly through the skin. Good times. This parasitic roundworm causes ‘trichinosis’ and various infections and disease. The movement of larvae through the body from the intestines and in muscle tissue that creates serious problems. The disease and health problems caused by these worms are noted world-wide. Which is of course, very bad news.

#7.   Body Lice


By now it should come as no surprise that Body Lice are blood sucking parasites, in this case ‘Obligate Parasites’ that live externally on warm blooded mammals which also includes birds. Body Lice are transmitters of diseases (Pediculosis) including ‘typhus’. Body lice live in a variety of dark spaces like in-between bedding and clothing where they lay their disgusting little eggs. They come out to feed on human skin several times in a day and as a result humans begin to suffer a variety of diseases including the aforementioned ‘typhus’, ‘trench fever’ and something called ‘relapsing fever’. Dirty little bastards.

#6.    Yellow Jacket

Yellow Jackets

As many of you are probably aware, Yellow Jackets are aggressive bugs that will inflict painful stings repeatedly, if you have the misfortune of provoking them. They are armed with lance-like stingers that have small barbs on them. Hence the painful part. Their venom is extremely dangerous to humans who are allergic, it can cause a very severe, sometimes fatal, allergic reaction. However, if you are stung enough times, allergy or not, all bets are off. Their predilection to make their nests inside man-made structures frequently bring them into contact with humans where attacks become more likely. If and when you encounter yellow jackets, get the hell out of dodge.

#5.   Africanized Honey Bee

Africanized Honey Bee

I’m not sure which is worse, the fact that the Africanized Honey Bee is an intentionally man-made creation, or the insidious damage that they cause. Also known as “killer bees” they’re a hybrid species that combines the Western honey bee (Apis mellifera), with the African honey bee (A. m. scutellata). Throw in a few genes from other smaller bees and what you get is…trouble. They were initially introduced circa 1950 in Brazil in the 1950s in an (ill-advised) effort to increase honey production. A noble idea that was turned on it’s head in 1957 when approximately 26 bee swarms escaped their quarantine enclosure. Not so good. They spread all over the South and Central America’s and moved directly into North America by early 1985. These bees are extremely dangerous because they attack swarm in the blink of an eye. They are easily provoked and sometimes attack without provocation. They attack in huge numbers and chase their victims with a laser focused vigor that is unprecedented, sometimes for a 1/2 mile or more. They’ve been known to wait for a person to surface after jumping into a pool to continue the attack. Also not good. These bees have killed thousands of people. In 2013 a swarm of 40,000 (yes, I know) killed a farmer in Waco, Texas (yes, that Waco). Stay way clear of these killers.

#4.    Deer Tic

Deer Tick

The common Deer Tic is responsible for many human diseases including ‘Lyme disease’,
‘Rocky Mountain Fever’, ‘Tularemia’, ‘Ehrlichiosis’, ‘Colorado Tick Fever’ and something called ‘Babesiosis’. This bug is yet another in a long line of blood sucking nasty parasites that uses mammalian and avian hosts to inflict damage. People who spend a lot of time outdoors in wooded areas are particularly at risk as they spread the aforementioned diseases to their hosts through their blood. Gross. Be aware of these little bastards when in wooded outdoor areas with tall grass, where long socks and cover your skin. You don’t want to get an extended blood sucking visit from these pricks.

#3.   Bullet Ant

Bullet Ants

It’s been widely communicated that a sting from a Bullet Ant is the most painful of any terrestrial insect on earth. In fact here’s a descriptive quote from Dr. Justin Schmidt who was bitten by a bullet ant: “It really felt like a bullet. It was instantaneous, almost even before it stung me. It was absolutely riveting. There were huge waves and crescendos of burning pain—a tsunami of pain coming out of my finger. The tsunami would crash as they do on the beach, then recede a little bit, then crash again. It wasn’t just two or three of these waves. It continued for around 12 hours. Crash. Recede. Crash. It was absolutely excruciating.” Any questions? I didn’t think so. Pray that this never happens to you.

#2.   Japanese Hornet

Giant Japanese or Asian Hornet

The Japanese Giant Hornet (Vespa mandarinia japonica) is aggressive, nasty and occasionally deadly. It’s the world’s largest hornet with an awe inspiring 6.25 mm-long stinger. It’s venomous and when inflicted it attacks the body’s central nervous system and damages skin and muscle tissue. This is one serious bug. How serious you ask? Well, if you get stung, besides the excruciating pain (only the bullet ant & warrior wasp are worse), you can expect a hospital visit. So I suggest avoiding getting stung in the first place, it will certainly ruin your entire day. This is one bug whose imposing size and appearance should be more than enough of a warning. Stay f*cking clear.

#1.   Tiger Mosquito / Mosquito


Mosquitoes are the scourge of humanity. They are a tireless spreader of deadly human disease and always have been. The good news is that there’s only 3,500 different species of them. Oh, wait, that’s awful news. They are responsible for the spread of the nefarious ‘Zika Virus’ which is related to other deadly viruses such as ‘Dengue’, ‘Yellow Fever’, ‘Japanese Encephalitis’ and ‘West Nile Virus’. All bad news, all the time. In 2015 a Zika Virus outbreak hit pandemic levels in South America. It is a disease that currently can’t be prevented by medicine or vaccines. It also has the added caveat of being able to be spread from a pregnant woman to her unborn baby. The worse news, ever. Mosquitos are in fact the worse insect humanity has ever known in terms of disease and it’s destructive toll on human life the world over. It should come as no surprise that they to, are blood suckers.