M.Sc. dissertation presented by Mrs Santosh Pokherel was performend under financial support from SMCRF. The dissertation aimed to access food habits and diversity of these food in the diet of bats. The study discussed food habits of bats of Mahendra Cave, Pokhara and Nagarjun Cave Kathmandu using fecal analysis; three white polythene plastic sheets (1mx1m) were placed for 24 hours under the roosting sites of each cave on starting and ending days of March and September of 2011 to collect fresh bat droppings. All together 120 droppings (60 from each cave) were randomly selected, observed under stereoscope to identify insects order and families. Altogether ten insects orders were reported viz Coleoptera, Diptera, Hemiptera, Homoptera, Hymenoptera, Lepidoptera, Odonata, Orthoptera, Tricoptera and Thysanoptera. The identified families were included highest in Diptera (seven families), following Coleopteran (six families), Orthoptera (five families) Hymenoptera (three families), Hemiptera (three families) and Thysanoptera (one family). In addition, spiders and mites were also reported. The percentage volume of the diet contained highest food items in Coleoptera (35.35%) and Orthoptera (24%) in spring and autumn respectively in Mahendra Cave. The other insects were Hymenoptera, Diptera, Hemiptera, Homoptera, Lepidoptera, Hymenoptera and Trichoptera. But in Nagarjun cave, Diptera was major portion of the diet in spring (28%) and autumn (24%). The other food items belong to Orthoptera, Thysanoptera, Coleoptera, Hymenoptera including spiders and mites. In Mahendra Cave, an average percentage of frequency of Coleopteran food items contained 63.33% followed by Orthoptera (46.66%) in spring. But Orthoptera occupied (50%) followed by Coleoptera (26.66%) in autumn. In Nagarjun Cave, Diptera was highest both seasons. The diversity of insects consumed in autumn and spring in Mahendra Cave was more or less similar (H’-0.77 and H’-0.70) with Nagarjun Cave (H’-0.76 and H’-0.71) respectively.