To hear a little better, you might cup your hand to your ear. Researchers have long figured that some bats may use the folds and grooves on their faces for a similar purpose. Based on computer models, researchers have now found that these structures cause some frequencies of ultrasound to focus in different directions than others. Wrinkly-faced bats may therefore have a variety of sonic "flashlights," each with its own pattern and direction, the group reported in last week's Physical Review Letters.