The phrase "dead bat" refers to a situation or response that lacks emotion, enthusiasm, or any apparent reaction. It implies a complete lack of interest, energy, or liveliness. Full definition
The insects» strange genitals may be a by - product of where they live: barren caves with little food except dead bats and bat guano. (newscientist.com)
«We find fewer dead bats at these treatment turbines,» says Cris Hein of Bat Conservation International (BCI). (scientificamerican.com)