5 Gross Facts About Flies

A House Fly vomiting on its food.

To most people, flies go down as one of the most annoying and hated animals in the known animal kingdom (it’s a tie between them and mosquitoes). This is due to the fact that lots of humans today associate flies only with negative adjectives, like ‘unsanitary’ and ‘bothersome’ (and for good reason)! Even the most fearsome animals can’t escape being ruthlessly bitten, stung and hounded by them. It’s a real shame that most living creatures get hassled by flies, considering that flies (all 120,000 known species of them) are still going strong. They still seem unfazed by manmade pesticides, fly swatters (that never seem to fall fast enough to actually even swat a stupid fly), and every other weird method we have tried to get rid of them with. Since flies aren’t going extinct any time soon, here are some facts to make you “appreciate” them in all their filthiness.

5. Spread of Disease Through Flies                                                                      

Flies can’t actually chew your food if they land on it, so the fly vomits stomach enzymes that break up the food for them to slurp with their proboscises. In addition, many houseflies will lay eggs on the food they are snacking on. If you are worried about getting sick from the acid vomited out the fly’s stomach, don’t fret (that’s only half your problem)! The real problem is the fly’s hairy legs and arms that could instantly infect it with Cholera or E. coli (or who knows what else) when it lands on your food. All this only takes a split second, so there’s no avoiding it if a fly lands on your food. Happy eating!

4. Maggot Infestation

Most breeds of fly can lay maggots inside you. They will be more likely to choose you if you have an open wound that’s easy to reach, or you’re just unclean in general (and that’s why even healthy people take baths), but a couple types of flies (screw flies, botflies, etc.) can start a maggot infestation in unbroken skin. I suppose you’d just have to be really, really, unlucky for that to happen. Anyways, if you let the maggot live under your skin (for…research purposes?), it will eventually burst out your skin, after having its fill on your flesh and blood, as a full grown fly (have you ever heard of a nastier sentence)?

3. Headless Fruit Flies  

Fruit flies, a subspecies of fly, can live for several days without their wings, or their heads (but not both)! Some laboratories have genetically engineered a fruit fly generation that lives a mostly normal fly’s life (in a lab, at least), unaccompanied by wings.

Fruit flies doing what fruit flies do!

Female fruit flies have also been documented in genetic labs to live for a few days completely headless, and still doing activities such as preening themselves, walking (when forced to), and flying. The males will still try to court the females, despite their clearly headless state (which isn’t actually very surprising). Geneticists ability to modify and engineer fruit flies to live without such vital parts of their body makes me wonder if the same could be done to humans. Could we somehow remove a vital organ from a human’s bloodline? Any volunteers?

2. Nasty Breeds of Botfly  

Botflies are by far the queen bee (ha!) of the fly world, and as such, I cannot just make a list of the worst/grossest things about flies without mentioning the little nightmares. There are many different types of botfly, most of which sting or bite mammals, and some of which lay eggs under their skin (as mentioned earlier). Some botfly subspecies have truly fabulous names and purposes, such as:

• European Deer Nose Botfly: Deer Nose Botfly larvae are called stag worms (as they apparently only affect male deer). They sometimes copy bumblebees, making it easier for them to trick deer into inhaling them. Maggots can be discovered living in most places on a stag’s head, like the bone that it’s head rests on, but lives most commonly in the nose (duh) or in the space by the beginning of it’s tongue.

• Tree Squirrel Botfly: Tree Squirrels with this botfly can be easily seen in parks, as the lumps can be quite big in size. Luckily, the Tree Squirrel botfly isn’t much harm to tree squirrels; a healthy, well-fed squirrel can survive with 5 or 6 of them no problem. These botflies are much more tame and harmless then many other types of botfly, especially the human one, but death can occur if there is a large infestation of botflies on a sick or pregnant squirrel (which is pretty rare).
  

  A lovely picture of a tree squirrel with a botfly infestation.

• Horse Stomach Botfly: They get into the horses’ stomach by resting on the horse’s leg and being licked up by the horse while it is grooming itself. They eventually end up in its stomach, where they grow and rest until they are full grown, at which point they fall out with the horse’s feces. It is possible for a horse to host about 100 botflies in their stomach at one time without showing any exterior signs of having a botfly infestation.

  1. Defecating and Vomiting House Flies                                                                                                                                                                                           

House flies, the most common and the most human-interactive type of fly, defecate an estimated 3-5 minutes every day, on basically any surface they can land on in time to, uh, evacuate their bowels. This can happen anywhere, anytime, including when a fly lands on you! Although this doesn’t happen every time a fly lands on a human, it’s certainly possible. Flies taste with their feet, so, if they think you taste good, (keep in mind that, from a fly’s perspective, dog poop tastes good, so you’d better hope the fly doesn’t think you taste good!) they might just vomit stomach juices on you in an attempt to liquefy your skin into something fly edible. Luckily, house fly vomit is not actually strong enough to break down human skin, but you still have to think about that tiny speck on your arm or leg that could carry disease.