One of the most common cave bats in Thailand often roosting in colonies of thousands. There is a small limestone hill 3.5km away from us and every evening 10-15 minutes after sunset a silent wave of these bats passes through our garden as they spread out over the surrounding ricefields to forage for insects. There are never a lot, perhaps 20-30 individuals, but noticeable if you're in the right place at the right time and don't mind the mosquitoes.
