The ecology of S. saccolaimus varies somewhat according to subspecies and region. In the Nicobar Islands in India, it is found in dense forests near the coast. In Sri Lanka, it has been recorded from dense forests, swamp habitat and plantations. There, diurnal roosts include hollows of old and decaying trees including Kitul Palm and Arecanut Palm, old buildings and rocky crevices in small colonies of five or six. No sexual segregation is observed in roosts. This species is known to feed on termites, beetles and other insects and sometimes forages close to the ground in open areas. It is also known to fly fast and high, up to 300 – 400 m from ground, and over forest canopy. It is recorded to emerge very early in the evening from its roost to forage (Bates and Harrison 1997). In South East Asia, the species is commonly observed over modified habitats, including agricultural areas. In some parts of Asia, roosts have been observed in buildings and shallow caves, sometimes in large groups. In the Philippines, roosts have mainly been observed in hollow coconut trees (L. Heaney pers. comm. 2006). In Australia and Melanesia S. saccolaimus has been recorded in dry open sclerophyll woodland, tall open eucalypt forests, dense tropical moist forest, open Pandanus woodland, and coastal lowlands. It roosts mainly in tree hollows, with colonies ranging in size from a few individuals to several hundred animals. Females gives birth to a single young (Flannery 1995a,b; Bonaccorso 1998; Hall et al. 2008;). 

Saccolaimus saccolaimus has been recorded from many protected areas, and over much of its range no direct conservation actions are needed. In South Asia, the species has been recorded from protected areas such as Campbell Bay National Park (Andaman and Nicobar Islands) and Kanha National Park (Madhya Pradesh). Further studies are needed on distribution, abundance, breeding biology and general ecology of this species. In South Asia, populations of this species should be monitored to record changes in abundance and distribution. There is also a need to identify populations that are being threatened by human induced habitat alterations in order to develop mitigation measures (C. Srinivasulu pers. comm.). It has been recorded from several protected areas in Australia, however, there is a need to identify and protect important roosting and foraging sites for the species. Further studies are needed in Australia into the distribution, abundance, natural history and threats to this species. Work to better characterise its echolocation call in the context of other low-frequency emitting bats would help environmental assessments. Taxonomic studies focussing on the Australasian populations need to be completed.