Bats have a lot of unique and interesting adaptations. For example, most bats spend the majority of their time upside down and some feed on the blood of other animals. They are also the only mammals that can fly. But perhaps the most impressive feature of bats is their ability to hunt using echolocation. With echolocation, bats send out high-frequency clicks as they fly. Then, they listen for the variations in the echoes that come back, which indicate the location of nearby insects. Using this system, they are able to feed on about 1,000 bugs per night, all caught on the wing.