A substantial component of the mosquito's sense of odor, or olfactory system, is devoted to sniffing out blood sources. This saliva serves as an anticoagulant with no it the feminine mosquito's proboscis may develop into clogged with blood clots. Depinay et al. (2005) observed a suppression of antibody-unique T cell responses mediated by mosquito saliva and dependent on mast cells and IL-10 expression.