Trypophobia is the fear of clustered holes like those shown in the lotus seed pod [seen right]. The lotus seed is the classic example of the sort of holes that frighten trypophobics, but sponges, soap bubbles and even aerated chocolate can be triggers. Trypophobia is not recognized in pyschiatry's Diagnostic and Statistical Manual of Mental Disorders, but it is present in 16 percent of people, according to a new study in Psychological Science, which is the first to address the strange fear.