Bat is an important keystone member in the ecosystem, which is the only flying mammal. It plays a vital role in maintaining eco-balance through propagation of vital flora.Bat has a major role in pest management in the forest. Bats give major indication for biodiversity conservation through propagation and pest management. Bats are also the key informers of climate change and its impact on their habitat. Bat species and their activity are useful to assess habitat quality and they serve as biological indicators of the ecosystem conditions and degradation. Diversity of bat species is studied using various techniques including speech recognition, voice recognition, artificial neural networks etc. and to detect the presence of bats acoustically. In this paper, the various computer techniques used to study bats are surveyed.