Why Do Horse Flies Dive Bomb My Car When I Get Home in the Afternoon?

Why Are Horse Flies So Bad This Year?

Last night, I accidentally locked a gigantic horse fly in the car with my daughter. She was not happy with me. I've noticed that they are really bad this year and was kind of curious why.

As a person who grew up with horses, I'm no stranger to horseflies. They are gigantic and scary and so, so gross. But they are also kind of slow, so they were always easy to smack and kill when they landed on one of my horses.

They also dive-bombed us a lot when we were kids in the pool and attack my car when I get home from work in the afternoon. Why do they do this?

Fun Facts About Disgusting Horse Flies

So first off... what is a horsefly?

Horse flies are in the family Tabanidae in the insect order Diptera and date back thousands of years. Ancient Greek author Aeschylus depicts a gadfly in one of his tragedies. They are also found pretty much everywhere in the world except very cold or very dry areas.

I was really surprised to learn that only females bite. They have a strong, incisor-like mouth where they cut a little hole and lap up the blood. They obtain a protein from the blood that they need to produce eggs. I know, ew, gross!

But males primarily feed on nectar and plant excretions. So if you swat a fly that landed on you that is trying to bite, you essentially killed a mama horse fly. I don't lose sleep over this.

a horse with a blinder on it's head

Why Do Horse Flies Bite People and Horses?

Horseflies lay their eggs in or near water, and when the larvae hatch, they feed on small insects and even reptiles. They then go underground and pupate for an entire year before they re-hatch into the big flies we see out and about.

That means the giant, bloodthirsty flies buzzing around right now have been developing for quite a while before they ever showed up to dive bomb you on pool day.

Why Do Horse Flies Attack Your Car?

According to MaggiesFarmProducts.com, female horse flies detect humans and animals by colors and movements. They are attracted to shiny objects, dark objects, warmth, sweat, and exhaled carbon dioxide.

So, if you drive a dark SUV, they probably think it's a large, delicious animal. They are coming in for a bite. It's nothing for me to hear three of four thuds on the sides of my car when I'm driving down the driveway in the afternoon.

And since they prefer warm, muggy days, these dog days of summer are prime horse fly season.

How Do You Get Rid of Horse Flies?

Unfortunately, horse flies can be tough to deal with because they are persistent and their bites hurt. If you're spending time outside, especially around horses, water or a pool, bug spray can help keep them away.

And if one lands on you and starts trying to bite?

Don't feel bad about giving that mama horse fly a good smack. Then step on it to finish it off.

Oh well. Good riddance, I say.