Some people have an innate ability to make your skin crawl. Outside of work, you can just walk away. But when you're forced to sit within earshot of said pest, or worse - work on the same team - things can get ugly.
So here's what to do if you're faced with a personality clash at work.
Cathy, an executive assistant from Sydney, says she's tried building rapport with a co-worker, but the stand-off remains intolerable.
"It's incredibly frustrating and disillusioning," she says.
"I had an (albeit unrealistic) idea that I could make her see how easy it could be to be a team player.
"This only had the effect of driving the wedge further.
"I can let things go quite easily, so there is not a noticeable rift. However, I don't trust her one bit and take everything she says as having an ulterior motive.
"I know this attitude is my responsibility to change, but it's difficult when I get stung every time I extend an olive branch."
Cathy says she doesn't respect her co-worker. Managers "turn a blind eye".
"My set of values are completely different to hers and it is impossible for me to empathise with her as a result," she says.
"Essentially we achieve nothing together; paired up we are not productive at all.
"I am hoping that the official step (I've taken) of involving HR will give the situation gravity."
Out of the frying pan
Michael White knows all too well how nasty workplace clashes can get.
While working overseas as a restaurant manager in his 30s, he learnt lessons that eventually paved way to a different career.
"The conflict between myself and the head chef came very close to trading blows," he recalls.
"It went a long way beyond verbal abuse, into the realms of extreme aggression.
"Under stress, people become quite irrational, and whatever other people say at times like that can either push a person over the edge or bring them back. We often went with the former.
"Our personalities were very different and we each had a different approach to running our departments," he says.
White got past the conflict by learning more about human behaviour.
"I ended up doing a conflict resolution course and found out about personality types," he says.
"I tried out at work what I learnt in the classroom and things changed. I became more responsive and less reactive.
"While things between the chef and myself got a lot better, we never became friends.
"I realised a while later that we did not need to be friends, but could be fellow professionals who did their best work to make the experience for the client the best it could be."
White now works as a personal and professional development trainer and life coach and created Aus Identities, a self-awareness programme that is used in some Queensland schools.
"If I could go back to day one at that place, and even before to some of the other restaurants that I worked in, I would try to understand where the other person was coming from and what personality type they were before I either started judging them or telling them how to improve," he says.
It's not you, it's me...
Some people instinctively dislike others from the outset.
Director of Inspirational Workplaces, organisational psychologist Helen Crossing, says "people definitely have a radar for those who interest them - and those who do not".
If you find yourself instinctively disliking another, you may need to check yourself.
"It is likely that something about this person threatens us, makes us feel uncomfortable, and potentially detracts from our own sense of self-worth," Crossing says.
"It can be looking at the person, and seeing in that person aspects of ourselves that we do not like and do not own, aspects of ourselves that we disavow.
"It can also result from a fear of the person - what they are wearing and what they stand for threatens us in some way."
Managers play a big role in helping workers co-exist harmoniously.
"The idea is to give people roles and talk about how well people perform in their role - not talk about personalities.
"It is impossible to change personality, so to focus on this leaves people unable to resolve differences.
"There are also laws that cover discriminatory practices in the workplace - people cannot be selected or promoted on grounds other than suitability for role."
Crossing says clashes in the workplace "waste time, energy and prevent tasks being done that further the interests of the organisation".
"If people are fighting and worried about popularity, favouritism and job security, then it's unlikely that they are productive and effective," she says.
"In this environment, it is likely that customers are forgotten."
Bosses should separate a mismatched pair only if there is a threat to safety, says Brooke Taylor, occupational therapist and executive general manager of Injury Treatment.
"It is difficult to believe that a proximity-based solution to poor behaviour would have an effective result if the people issues at play go unaddressed," Taylor says.
"We might expect that employees with unmitigated issues will come into conflict with other colleagues.
"An initial separation or move of individuals may just allow them to rope in a new team in support of an old argument," Taylor says.
Taylor says businesses should celebrate staff individuality and the unique skills that different people contribute to a team dynamic.
"Quirks and characteristics only become an issue when they contravene organisational boundaries," she says.
"In order for small business to better manage these quirks, organisational boundaries for behaviour and communication need to be explicit and well-publicised."
Taylor says small business owners should remain vigilant to behaviour that suggests a butting of heads is escalating.
"There is little doubt that the grating and grinding of personalities in the workplace environment can evolve from water cooler talk to a worker compensation claim faster than an offending staff member can announce that they 'don't suffer fools lightly'."
- Sydney Morning Herald