For the prevention of Visceral Leishmaniasis i.e., Kala-azar, the control of its vector which are commonly called sandflies is mandatory. This can only be achieved when the bionomics of this vector is properly known. The basic aim of this research work is to reveal every hidden feature of the sandfly behaviour as far as possible. Study of each and every stage of sandflies helps understanding the effects of environmental and climatic factors on them. All types of studies on sandflies would prove imperfect unless and until the behavioral pattern of sandflies are explored fully. This book includes findings on bioecology, binomics including behaviour of sandflies in State of Bihar, India. Work to explore different aspects of sandfly biology was carried out both in field and under Lab conditions. This work would help entomologists/epidemiologists/public health experts/health department for successful control of this vector.