When I noticed a rat crawling underneath a bush in a public area who was desperately trying not to be discovered. I was eager to try to shoot him. Aperture , shutter speed and pre-focus the distance .... and waited until he turned to my side and click!!! City rats are living among us in cities and some said there are more rats living in towns than humans! They mostly come out when nearly all people are sleeping! This one must be suffering from insomnia !