Phobias are commonly thought of as 'irrational' fears, but if you suffer from Trypophobia you may have a good reason.
Trypophobia is the fear of irregular patterns or clusters of small holes and lumps. The name is currently only a proposed phobia, and is not recognised by American Psychiatric Association.
Where does this exist in nature? Quite a few places actually, such as lotus seeds.
In normal human life, they're everywhere too, like on a foamy coffee, soap bubbles, and chocolate chip cookies.
Psychologists at the University of Kent believe the phobia may actually be a heightened aversion to parasites and infectious diseases.
In the past it has been thought the clusters of round shapes reminded people of poisonous predators (think spiders and their many eyes).
Tom Kupfer, leading the team at Kent's School of Psychology, believes it may actually be a reminder of the clusters and round bumps that can develop on human skin after an infection or when a parasite has burrowed under the skin.
Such groupings of small circles can occur on the bodies of those affected by smallpox, measles, scarlet fever, rubella, and typhus.
Approximately 600 people, half sufferers from trypophobia and half non-trypophobic university students, were shown 16 images of clustered circles.
Eight of the images were of skin clusters caused by a disease or parasite. Both groups found these images unpleasant, whereas only the trypophobics found all 16 uncomfortable.
The 'phobia' may be more of an aversion, like when people see something disgusting.
Interviewing suffers of the conditions, researchers found the feelings they described were more akin to sickness than to fear or fearfulness.
They also frequently describe the sensation as 'skin crawling' or itching, which could support the idea its linked to parasites.