Radars can be used to detect and identify all sorts of moving objects. David Pye demonstrates a handheld one and also shows how birds and planes can be detected. Watch the full lecture: http://www.rigb.org/christmas-lectures/watch/1985/communicating/the-bionic-bat?utm_source=youtube&utm_medium=social&utm_term=description David Pye gave the 1985 Christmas Lectures "Communicating" about the incredible world of communication. From the man-made satellite dishes to the complex biological system of bat communication. The third lecture, titled "The Bionic Bat", where this clip is from, is all about sound and how it's used for not just communication but also echolocation. Watch the full series: http://www.rigb.org/christmas-lectures/watch/1985/communicating?utm_source=youtube&utm_medium=social&utm_term=description The Ri is on Twitter: http://twitter.com/ri_science and Facebook: http://www.facebook.com/royalinstitution and Tumblr: http://ri-science.tumblr.com/ Our editorial policy: http://www.rigb.org/home/editorial-policy Subscribe for the latest science videos: http://bit.ly/RiNewsletter