Partly drunken beers left on tables overnight after parties. Preferably in plastic cups. Or left out for several days or even weeks or months. Possibly with cigarette butts in them. Possibly growing things too. Turning green or red.
When public employees, especially police, fire, toll and emergency workers, hide away somewhere away from the public, possibly together, in order to goof off on the job, or pad their hours, especially for overtime pay.
Joe pulled in 2000 hours of overtime last year from cottaging on the job.