Fly Trivia:Why can the fly hang upside down on the wall?

Although it looks like a smooth surface, there are also many tiny cracks and bulges that are invisible to the naked eye. These become the attachments of the feet or hair of insects such as flies.

At the end of the fly's foot there is a claw-like part called the tibia, and the bottom of the tibia has a pad - a large foot pad.

The mattress is covered with a number of hard bristle-like bristles that produce a gel that allows the fly to easily attach to a smooth surface, but can also take off quickly.