This story originally appeared on BusinessInsider.com.
Costco jobs aren't always a cakewalk.
Sometimes, that's due to the behaviors of Costco members.
A 2018 study from the University of British Columbia found that the promise of deals can "lead consumers away from fully recognizing the human qualities of employees."
While the retail chain made Glassdoor's list of best places to work in 2017, employees have still occasionally taken to social media to complain about bad behavior from shoppers.
"It's crazy how rude the American shopper is to people they don't know — who are helping them," a Costco employee from Utah told Business Insider.
However, one California-based Costco worker told Business Insider that they haven't had too many problems with members. "We get paid incredibly well to deal with the members, so unless they're being crazy — admitting to stalking you, being racist — we'll deal with it," the employee said.
Here are 24 annoying behaviors that are sure to irk Costco employees:
Treating employees poorly — then expecting them to 'bend over backwards' for you
Rude customers are a problem that most retail workers come up against. Costco employees are no exception.
In a 2013 Reddit AMA, a Reddit user who said they'd worked at Costco for seven years estimated that they hated 80% of the members that visited the store.
"Because people pay a membership fee to shop there, they feel entitled to treat us like s--- and expect us to bend over backwards for them," the employee wrote.
A Costco food court employee wrote in a 2014 Reddit AMA, "I'm not some indentured servant. I'm a person that has lived a life just as full as yours. I just so happened to end up on the other side of the counter today."
A Costco employee based in Ontario told Business Insider that members "pay a small fee for amazing deals — not a bunch of slaves."
A Costco employee in Texas, as well as a Costco optical department employee, also reached out to Business Insider to say that they wished some customers would drop their "belittling" and "entitled" attitudes.
Trying to shop at Costco without a membership
Costco employees are sometimes forced to deal with non-members trying to shop at the warehouse.
In a 2016 Reddit thread, a Reddit user who said they'd worked at Costco for eight years wrote that their go-to response to indignant non-members was, "I do apologize, but it is Costco's policy. It is a membership-based warehouse, and if you are not a member then you cannot shop here."
Causing problems at the front of the store
Costco members can easily make life difficult for employees monitoring the front entrance of the store.
A Reddit user who said they'd worked at Costco for eight years as of 2016 wrote that annoying behaviors include customers failing to show their Costco member card, blocking the front entrance, and "pulling the 'but I've shopped here for year' excuse' in lieu of a card.
A California-based Costco employee told Business Insider that they wished members would stop "giving attitude when asked to see their membership card."
An Ontario-based employee told Business Insider that they wished members wouldn't get annoyed when asked to show their membership card at the front of the store.
"We don't do that because we're judging you or because we think everyone is a criminal," the employee told Business Insider. "If we let anyone in with or without membership, we'd have incidents where people will fill their buggy to the rim, proceed to check out, and, when the cashier asks for their membership, they act like they never knew that they needed one."
Making patronizing assumptions about employees
Want to avoid ticking off a Costco employee? Don't assume they're looking for a better job.
In an op-ed article in Refinery29, a former Costco employee named Meghan DeMaria said she loved working at the store and resented the implication that her job was "any less real or important" than any other.
Failing to watch where you're walking
A Costco employee who's worked for the warehouse chain for two years said they got annoyed when shoppers "... randomly stop walking, or cut off employees."
That goes double for when employees are carrying heavy objects.
"Pallets are heavy, and it's extremely hard to come to a complete stop immediately," a Costco employee told Business Insider. "Watch out for employees pushing or pulling things bigger than you."
Leaving out perishables
"The worst thing that pisses me off is people that leave perishables sitting in the aisles," wrote a Reddit user who said they worked at Costco in 2017.
Customers stashing juice and cheese in the freezers also irked this poster.
A Costco employee in California told Business Insider that they had noticed members removing perishable products from the store's freezers and then simply leaving them out to "go bad."
"I wish they wouldn't grab frozen products and then, when they decide they don't want it, leave them wherever," an employee from Ontario told Business Insider. "The product goes bad and becomes garbage."
Abandoning your cart while in line at checkout
When you're in line at checkout, stay in line. Especially if you're buying a ton of stuff.
In a 2013 Reddit AMA, a Reddit user who said they'd worked at Costco for seven years described one customer who just vanished from the line, leaving his basket of items and a credit card on the conveyor belt.
The employee described it as the "most annoying thing you can do to an employee."
Leaving carts around
"Members leave their carts on the islands and curbs instead of walking them to a corral," a Florida-based Costco employee told Business Insider. "I don't understand how they can walk around the whole store — which is pretty big — but suddenly be too exhausted to have manners and just return the cart. It's empty, so it's easier to push now."
Two Costco members also reached out to Business Insider and corroborated this account.
"Their motto is to let somebody else take care of the carts, rather than put them in the cart corrals," a regular customer in Florida told Business Insider. "Maybe there should be a training program for Costco customers."
One member in Maryland added that some members "leave their carts in the parking lot. Carts take the space of a car. Carts are put on grassy areas. Carts end up being a missile under windy conditions."
In general, it's a good rule of thumb to not make death threats.
But, in a 2016 Reddit thread about retail work, two users who said they worked for Costco said they had received death threats from members on the job.
"I fully believe that bad customers have never worked retail themselves," wrote one of the Costco workers.
Attempting to start physical fights with the employees
Some customers go beyond rudeness and actually resort to violence in Costco stores.
A Reddit user who said they'd worked at Costco for seven years described having a customer attempt to start a fist fight in a 2013 Reddit AMA.
As the story goes, the individual in question had left the line at checkout to go grab bread, and the Costco employee rang up the people in line behind him.
When the member returned, he became infuriated after being told he had to get back in line.
"He got right in my face telling me he could lay me out right then," the Costco employee wrote. "I remember telling him that if he hit me I'd get some paid time off from this place, so go for it. Management kicked him out because he was causing a huge scene. Members clapped when he left. I felt like a hero."
In her Refinery29 piece, DeMaria also noted she was once slapped by a member during "an argument about the membership she was using."
The occasional threats of violence from some members disturb Costco customers as well. One Washington-based customer told Business Insider that they had "seen several battles over a parking spot almost turn to fisticuffs."
Complaining about store policies
Like most workers, Costco warehouse employees do not have the power to change company policy on a whim.
But that won't stop some Costco members from bugging them about it, according to DeMaria.
One Kentucky-based Costco employee told Business Insider about members asking them to establish store fitting rooms or "get their favorite product back in stock."
"I'll help them find another store that's got it, but I can't make that item magically appear because they complain about it," a Costco employee in California told Business Insider.
Getting employees into trouble with management
An anonymous Quora user who said they previously worked at Costco wrote that, in some instances, members go out of their way to get workers in trouble.
"Members can be rude and mean to employees and then complain the employee did not do enough to help them or lie and say the employee was rude or disrespectful," the anonymous user wrote. "The member's word will always be believed 100% of the time and the employee will get in trouble."
Former Costco employee and Quora user Alex Barrett wrote that Costco gigs came with "the same annoying ills of any customer service job," including "having the most vile, disgusting creature of a customer vomit rudeness all over you and then say it's your fault, and you either have to smile and take it or watch as your manager gives them a free pizza as an apology for the horrible experience they self-generated."
Asking overly personal questions
DeMaria wrote about how some customers would ask employees rude questions about their salaries and education levels.
"Questions like these fed the idea that working in retail or in a big-box store is somehow not a 'real' job — and they're a great way to kill morale," DeMaria said.
What's more, "it's certainly none of your business," she wrote in Refinery29.
Getting upset when the warehouse is closing
An Ontario-based Costco employee told Business Insider that some shoppers get irritated when the store starts closing down for the night.
"We ask members kindly to head to the front and check out, because our store is closed," the employee told Business Insider. "Sometimes, we will help them grab a last minute object. I wish they didn't treat us like pushovers and get mad at us for not letting them continue to browse or shop. They had all day, and we don't run on their time."
Failing to control your kids
"Sometimes parents don't hold their kids hands in the warehouse," an employee from Ontario told Business Insider. "The kid sprints around the aisles. And there are forklifts on the floor. It ticks me off every time."
Not using common sense at the gas station
A Costco gas station employee told Business Insider that they often have to provide common sense pointers to some members.
"Do not turn your car the wrong direction," the employee told Business Insider. "It is one-way traffic. Always stay inside the lane."
Leaving trash around the store
"I wish customers would stop leaving trash everywhere," an employee from Ontario told Business Insider. "I wish that, when they try a demo with those plastic spoons, tooth picks, and cups et cetera, they would throw it out in one of our a hundred plus garbage cans laid out in the store."
Making outrageous returns is rarely a good look
Costco has a notoriously-lenient return policy.
And, according to employees, plenty of people are happy to abuse it.
Used underwear, an entire flatbed cart full of food, a urine-soaked mattress, 13-year-old fish, and a weekly shipment of rotten avocados are a few of the more egregious returns that customers have actually gotten away with.
A California-based Costco employee told Business Insider that it's always annoying when people try to return "things that are 10 years old and 'just stopped working.'"
"We can't say 'no' to any members, so don't bring anything back that's 10 years old — such as a fake Christmas tree we got back that was sold in 2007," a California-based Costco employee said. "We want to help, but that sets a bad example for everyone to bring anything back."
A Costco employee of 12 years told Business Insider that they wanted customers to "... stop bringing half-eaten food and saying it was bad."
They added that they've seen shoppers return clean-picked bones and explain that the "... meat was no good, but they had to feed their family something."
Flirting with employees
"There was one man who I saw tell a cashier she was 'a looker' — she was clearly uncomfortable, but powerless in the situation," DeMaria wrote in Refinery29.
Being distracted by your phone
Three Costco employees in Iowa, Hawaii, and Florida, respectively, said too many customers are distracted by their phones in the store.
"If you are in line for checkout, please don't be on your cell phone," a Florida-based employee told Business Insider.
Making a mess
A Kentucky-based Costco employee told Business Insider that some members bring in "fake service animals that bark and defecate in the store" and then fail to clean up after them.
An employee in Illinois told Business Insider that members also need to stop "eating a thousand samples and leaving their garbage everywhere."
An employee who's worked at Costco for 25 years agreed, saying, "We have garbage bins at every sample station, along with at the end of a few aisles. Then there are garbage bins outside around the store. Yet sample cups end up sitting in the cart with leftover pieces, juice, and sauce in them. Very messy."
Making the same old jokes
A number of Costco employees told Business Insider that it's high time to retire one ubiquitous joke.
Four employees in Washington, Hawaii, Minnesota, and Arizona said they never want to hear a customer say, "If it doesn't scan it must be free!" ever again.
"It wasn't funny the first time we heard it, and it isn't funny after we've heard it 62,000 times," a Costco employee from Minnesota said.
Hassling the employees about food court options
"There's one guy that keeps asking for whipped cream on the coffee drink, and I keep telling him we don't have that," a Reddit user who said they worked in the Costco food court wrote on Reddit in 2014. "He calls me by name when I'm in the back making pizzas even, saying I told him there was whipped cream to my boss. It's annoying."
One employee from Pennsylvania told Business Insider they got annoyed when customers tried to "rush cooking time" in the food court.
Being careless in the parking lot
Watch where you're going in the Costco parking lot.
"We have to wear reflective vests, and I swear those things are just a bright orange flag telling everyone, 'Hey I work here so you can say or do anything to me and I won't do anything about it,'" Reddit user who said they'd worked at Costco for seven years wrote in a 2013 Reddit AMA.
"I've been almost hit by so many cars it's ridiculous," they wrote. "Afterwards more than half the time I get yelled at because I didn't get out of the way."
A Costco employee from Oregon told Business Insider that they've seen people park their cars right in front of the store entrance, adding, "People need to come and go, and they park their car right there in the way."
Bad behavior in the parking lot doesn't just affect workers. A Costco member told Business Insider they saw a group of customers just standing around in the parking lot tying up traffic.
"No one could get through, as they were blocking both lanes," the member told Business Insider. "The cars started honking. They didn't move after the first, second, or third polite tap of the horn. They waited until someone laid on the horn until they moved."