Abstract
Avoidance of pathogens is crucial for one's survival. The mechanisms responsible for pathogen avoidance are known as the 'behavioural immune system', which consists of various perceptual, affective, cognitive, and executive processes.
In this chapter, we review current knowledge on pathogen avoidance in mammals mediated by odour cues. We start with an overview of changes in the body odour caused by pathogens.
Then, we summarize current evidence regarding the avoidance of odours of infected individuals with emphasis on rodents and humans, and discuss the effects of multimodal integration on avoidance behaviour. We also review possible physiological mechanisms of pathogen avoidance, such as a decrease in pain sensitivity and hormonal involvement, including oxytocin, vasopressin, cortisol, and the sex hormones.
Finally, we discuss ontogenetic development of pathogen avoidance. In conclusion, we outline some directions for future studies and point to the need to study a broader range of species.