Do You Know?

Northern Advocate, 26 January 1939, Page 9

Do You Know?

HOW a Fly Walks Upside Down iliaye you ever wondered, when you have been watching a fly stroll leisiwely' across the ceiling, hbw it is he manages to walk upside down like that? It is only the tiny “sucker” on jfie tip of. his . tiny feet that hwtes it possible ' for him to do this. You know if you round piece of rubber or leather that is bell shaped underneath and put a piece of 'larlng through the middle you will be able to pick l up a flat stone with it simply by pressing on the stone and then pulling gently on it: by the string.' The explanation of this is that wheri you press the rubber down over the stone you expel the air which is between the rubber and the stone; this creates a vacuum, and the pressure of the air on the outside part of the] leather enables you to pick up the stone, Now. the tiny suckers on the fly’s feet work in exactly the same Way, the sucker acts automatically when he puts his foot down, making his foot stick to the ceiling or the * window pain. And the sticking power of each foot is adjusted to the weight of the fly.