Free-ranging dogs occupy a wider ecological niche from pampered pets and faithful servants to feral scavengers.The dog is man's best friend on the other he is the despised and degraded outcast.In recent years popular and scientific accounts indicate a growing awareness of problems posed by large populations of uncontrolled domestic dogs both in urban and rural environments. In this study many facets of the phenomenon of the urban free-ranging dogs were examined. The focus was on one town- Katwa West Bengal a town that is becoming greater in size keeping pace with the increase of human. This is a study both of dog ecology and behaviour. I hope that the ecologists will find it interesting and also find new data especially on dispersal and alloparental behavior of free-ranging dogs. Moreover the author hopes that this study will encourage the students to study the ecology and behaviour of free-ranging dogs.