This piece is part of an ongoing series exploring what it means to be a woman on the internet.

On Twitter, a place where a lot of bad things happen, there's a mostly harmless but decidedly annoying phenomenon. A lot of people, mostly women, have noticed that one or two men always, no matter what, reply to their tweets.

These men are colloquially known as "reply guys." While no reply guy is the same — each reply guy is annoying in his own way — there are a few common qualities to watch out for. In general, reply guys tend to have few followers. Their responses are overly familiar, as if they know the person they're targeting, though they usually don't. They also tend to reply to only women; the most prolific reply guys fill the role for dozens of women trying to tweet in peace.

Welcome to Twitter ladies. A married man, who mainly follows, and interacts with only women, will be assigned to you shortly — Shit. Head. (@THE_shitface) February 12, 2019

It's usually pretty easy to ID a reply guy. The sheer volume of responses is a reliable indicator. But there's still some literature on the subject. In a 2018 piece for McSweeney's, for instance, Emlyn Crenshaw wrote an extremely funny Reply Guy Constitution, which focuses above all else on men's commitment to "weigh in on women's thoughts at every possible opportunity."

And two scientists, @shrewshrew (who asked to be referred to by her Twitter handle only) and Scott Barolo, created the Twitter account @9ReplyGuys based on the experiences of women in STEM.

"We came up with the idea of the 9 Reply Guys after noticing that the kinds of tweets and comments make to women on Twitter (and in real life) follow really predictable patterns," @shrewshrew explained via Twitter DM.

"It's annoying because Reply Guys always think they've made some brilliant contribution, but it's the same nonsense any woman, person of color, or LGBTQ person has experienced hundreds of times," she said.

The account divides reply guys into nine subcategories, each based on a reply guy behavior the two observed in the wild. The Gaslighter, for example, is devoted to minimizing women's experiences, and the Cookie Manster is basically the poster child for #NotAllMen.

All nine have one thing in common, though, as @shrewshrew pointed out: "Their goal is to control the conversation."

#WomeninSTEM get a lot of “Reply Guys” who repeat the same unhelpful comments.@shrewshrew and I (a woman & a man in science) have attempted to catalog those replies, to save us all the trouble of writing new responses every time.



presenting THE NINE TYPES OF REPLY GUYS



(1/n) pic.twitter.com/0ewNRJloLu — Scott Barolo (@sbarolo) September 3, 2018

Reply guys aren't just lurking on STEM grounds, either. Petrana Radulovic, a reporter at Polygon, had a reply guy experience that was truly, deeply weird.

"I had this fella who followed me because I had Cookie Monster in my profile pic and he just kept replying to everything I posted trying to get me to talk about Muppets," she explained over Twitter DM.

Like most reply guys, he was relentless. Eventually, Radulovic muted him. Notably, though, she never blocked him.

"I have that internalized female niceness where I can't make anyone mad," she said. "I [also] fear men's retaliation and muting will keep 'em quiet, but they'll never know." (Users aren't notified that they've been muted.)

"Muting will keep 'em quiet, but they'll never know."

Another user, who asked to remain anonymous, said she's noticed several reply guys in her mentions. Unlike Radulovic's reply guy, her reply guys respond to each tweet individually. "It's always regarding the content of [my] tweets, contextual," she said. But it still happens like clockwork.

She's also chosen to mute instead of block. None of her reply guys are "consistent harassers," she said.

Still, reply guy behavior can escalate quickly — which is why a lot of women choose not to block the offenders. I once had a reply guy whose comments started off innocuous, then steadily became more frequent — and more suggestive — when I stopped liking his replies. Eventually, he also found me on Instagram and Facebook, where he continued to engage with the vast majority of my posts.

I didn't block him, though. I didn't want to make him angry. One never knows how far a man will go to make a woman's life hell.

hey i’m the guy who replies to your every tweet trying to one-up your jokes. i have 97 followers and while there’s nothing technically wrong with my facial hair, it’s not the facial hair any reasonable person would pick for this face shape. someday soon i’ll call you a cunt — rax king (@RaxKingIsDead) February 17, 2019

But what makes a reply guy reply in the first place? It's been suggested — including in a piece from Raw Story — that the reply guy phenomenon is an instance of benevolent sexism.

As with other types of benevolent sexism, like catcalling disguised as "compliments" and paternalistic pseudo-concern, reply guy behavior can quickly grow frightening if the man doesn't feel his target is giving him the attention he deserves. (Feeling entitled to women's energy has, of course, been a longstanding problem for cis men.)

If you're a woman on the internet, there's a high chance you find none of this surprising. But what should you do if you suddenly find a reply guy in your mentions?

Today on Maury: My Son’s a Reply Guy — alec (@tort_tweets) February 10, 2019

Of course, how you choose to deal with a reply guy depends on your specific circumstances. If you think you've got a shot at shooing them away, you could hit them with one of @9ReplyGuys's descriptions. You could reply, if you want. (Don't pretend you don't love a good dunk.) If you feel unsafe or if you don't want to see their garbage anymore, you could mute or block. It's your feed. They're the interloper, not you.

And if they get too annoying, you can always commiserate with ... thousands of other people on the internet. I'm sure they'd be thrilled to hear from someone who is not a reply guy.