Head, Zoology Department, University of Delhi, (2010- 2013) (Administration and Academics)
Professor, Zoology Department, University of Delhi, 1998 onwards (Teaching/Research)
Reader, Zoology Department, University of Delhi, (1992-98) (Teaching/Research)
Teacher Fellow (1980-85) Department of Zoology, Delhi University
Reader, Magadh University, Gaya, 1986- 91 (Teaching/Research)
Lecturer, Magadh University, Gaya, 1975- 86 (Teaching/Research)
(i) Post Doctoral Fellow, Max-Planck Institute of Biochemistry, Munich, Germany (1985-88)
(ii) Visiting Scientist International Centre for Insect Physiology & Ecology, Nairobi (KENYA), 2013