Let’s Talk About That Fly that Stole the Show This Week
By: Emily Kingsley
Tags: Nature, Education, Culture, Science

For many of you, the fly that landed on Mike Pence’s head during the debate was nothing more than a brief distraction from the crazy events of the past week.

But for me, a high school science teacher in the middle of an entomology unit, it couldn’t have been more exciting. I’ve spent every day for the last two weeks in zoom calls talking about what insects eat, how they mate, where they live, and why they’re important to us.

So when the whole country pivoted away from politics, wildfires, and protests to talk about a little black bug, I was delighted. Finally, something in my wheelhouse!

Two things that have surprised me over the last few weeks are how little my students actually know about insects and how much they like learning about insects.

I thought some of you might be in the same boat — woefully ignorant but interested to learn more about that cute little dipteran that made itself cozy on Vice President Pence’s snowy white hair.

So let’s dive in.

Getting to know the Fly Posse

Of course, you know that flies are alive. But you might not know that since they have sex, eat food, and are made of a whole bunch of cells, they are in the animal kingdom, just like us.

That’s where our similarities end, taxonomically speaking. While our bones are tucked away neatly under our skin, flies — as well as crustaceans, spiders, and trilobites — wear their support system on the outside. It’s called an exoskeleton, and it’s the part that goes ‘crunch’ when you squish a bug. Animals that have an exoskeleton belong to a large, cool group of animals called arthropods.

Within the arthropods, there are a handful of smaller categories called classes. Our friend Mr. fly belongs to the large, diverse class called Insecta. This class includes all arthropods that have six legs, three body segments, and two antennae.

Class Insecta is further divided into categories called orders. The order that Mr. Fly belongs to is called Diptera, and it includes some of the most deadly and annoying insects on the planet.

Insects that belong to the order Diptera have two wings and soft squishy bodies. Most of us love to hate the dipterans — included in this order are mosquitoes, gnats, midges, no-see-ums, deer flies, horse flies, greenheads, and other biting, slashing, sucking, and disease-carrying insects.

Humble Beginnings: Life as a Maggot

While it’s tough to identify the exact species of fly that starred in Wednesday night’s debate, there are some things we know for sure.

All flies start out as eggs. A fly egg is a little smaller than a poppy seed and creamy, white, and oblong. When the egg hatches, a very tiny maggot crawls out. Maggots have one goal — to eat and get bigger.

Often, a mother fly will thoughtfully lay her eggs directly on a food source so the babies have plenty to eat as soon as they hatch. So for many flies, the first place they call home will be the eyeball or anus of a dead animal, a pile of feces, rotting garbage, or the open wound of a living animal.

As the maggots eat, they grow rapidly. Yes, maggots are disgusting, but they do provide a service. Maggots break down unwanted organic material so that the earth isn’t overrun with dead bodies. It’s not glamorous, but somebody’s got to do it. Otherwise, we’d be up to our thighs in carcasses. I’ll spare you a more graphic description, but if you find yourself in need of a visual, look up some maggot videos on youtube.

Once the maggot is big and fat, it enters the next stage of life by forming a pupa. A fly pupa is the size and shaper of a piece of rice. It’s a hard shell wrapped around a gooey inside. You might have seen one before without knowing what was inside. While inside the pupa, the fly’s guts turn to liquid and then reorganize to form the body structures of an adult fly.

It’s called metamorphosis, and when a butterfly does it, it makes us feel all ‘change is beautiful’. But for some reason, a gross maggot turning to a piece of rice and then emerging as a hairy black fly doesn’t evoke the same emotion.

After a few days, the fly is ready to break free from the pupa. You might expect some kind of primal claw or tooth would do the trick, but that is not the case.

Instead, the fly uses an inflatable pouch on its face to break out of the pupa. You really need to watch it to believe, so take a minute and check out the video below.

Let the fun begin: Life as an adult fly!

Once a fly has escaped from its pupal prison, it is ready to begin life as an adult. Although there are lots of different fly species, all adult flies have two basic goals: find food and have sex.

Most flies have sucking mouthparts, which means they eat liquid foods. So if you’ve ever visited a farm and seen flies buzzing around, it’s because flies know that cows and horses are a great source for saliva, urine, sweat, and tears.

And if you’ve ever been bitten by a greenhead or a horsefly, the reason it hurt was that those insects have knife-like appendages on their faces that slice and dice your skin until blood drips out. Then they use a spongelike mouth to suck up your blood.

Mike Pence’s fly was probably a common bottle fly or a blowfly. These flies are not dangerous or special, and chances are you have one or two in your own house right now.

An interesting thing about these flies is that they have taste receptors — just like we have on our tongues — on their feet. So if you’ve ever watched a fly walking around and tapping its feet to the ground, it was searching out sugary substances to try to sop up with its sponge-tongue.

This is a guess, but I would bet that the Vice President’s hair had been slicked with a hair product containing some form of glycerin. Glycerin is a type of sugar, which explains why the fly stuck around. For the fly, tapping its feet on Mr. Pence’s hair was as enjoyable as licking a Tootsie Pop.

When a fly isn’t looking for food, it’s focused on sex. Female flies release pheromones that attract male flies. Although some insects perform elaborate courtship rituals and have acrobatic, in-flight sex, flies have a pretty boring sex life. After doing a little bump-and-grind dance together, the female fly slides a tube called an ovipositor out of her abdomen and into the male.

Sperm travel from the male into the ovipositor. They fertilize the eggs inside the female's body. The female then uses her ovipositor to dig a little hole in feces or the flesh of a dead animal and then deposits her eggs.

And the cycle begins again!

Isn’t life beautiful?