Watch on SFlix. The fearsome bat is amongst the stealthiest hunters in the Animal Kingdom, but for all their ingenious abilities, a species of grasshopper in the mountains of Bulgaria has learnt to outsmart them. Now, join a team of researchers armed with state-of-the-art ultrasonic cameras, as they discover the mechanisms behind this standoff. The Secret Life of Bats reveals the science behind sonar, and the hidden hunting challenges faced by this deadly predator.