Two guys were working for the Chicago Streets and Sanitation Department. One day they were seen doing an extremely odd thing:

one would furiously dig a hole, then the other would come behind him and quickly fill it up. They were drenched in sweat.

A man watching from the sidewalk couldn't believe how hard they were working, but also couldn't understand what they were doing.

Finally he said, "I appreciate how hard you're working, but I'm confused. You dig a hole and then your partner comes behind you and fills it up again!?"

The digger leaned on his shovel and replied, "Oh yeah, it must look funny. You see, the lazy jerk who plants the trees called in sick again today!"