Correct answer. Small / micro bats use echo-location for their food, prey and survival.
Flying mammals belong to order Chiroptera, where forelimbs are modified into wings to help them fly. Flying mammals mainly include bats belonging to two sub-orders-frugivorous, large bats (Pteropus, Cynopterus) are placed in sub-order Megachiroptera while Microchiroptera include insectivorous little bats (Myotis, Rhinolophus, Vespertilio and Desmodus). The microbats use echo-location to detect their surroundings, prey, path etc.