Biological interaction between two organisms living together in a given habitat is essential for healthy ecosystem functionality, got complexity, and exerts an arms race between the interacting organisms. Some vectors are exclusively blood feeders, and others supplement their diet with plant nectar. The feeding dynamics may determine their olfactory system complexity. Arthropod vectors that interact with livestock rely mainly on olfaction. Livestock odor profile is a complex trait and depends on host genetics, microbes, diet, and health status, which highlights its dynamic nature. Furthermore, volatile metabolites are shared between host animals, which exert its own challenge for vectors to find their preferred host. Elucidating the underlying host chemodiversity, especially signature scents, neuroethological mechanism of discrimination of preferred/unpreferred host from plethora of coexisting host is crucial to understand evolution and adaptation in vector–livestock interaction.