Read here disgust
“the emotion of disgust has evolved as a response to offensive foods that may cause harm to the organism. A common example of this is found in human beings who show disgust reactions to mouldy milk or contaminated meat. Many researchers have claimed that the emotion of disgust functions to protect us from disease. Disgust appears to be triggered by objects or people who possess particular types of features that signify disease.”
Self-report and behavioural studies found that disgust elicitors include
body products (feces, urine, vomit, sexual fluids, saliva, and mucus)
foods (spoiled foods)
animals (fleas, ticks, lice, cockroaches, worms, flies, rats, and mice)
hygiene (visible dirt and “inappropriate” acts e.g. using an unsterilized surgical instrument
body envelope violations (blood, gore, and mutilation)
death (dead bodies and organic decay)
visible signs of infection
The above-mentioned main disgust stimuli are similar to one another in…....read on at link”