Back in my college days, a buddy of mine had a summer job as a night watchman at a barge repair company down on the river in Pittsburgh. We'd occasionally go down to visit him at night, since his duties were actually pretty boring. As we'd walk along with him on his rounds, we'd assist him in one of his responsibilities: taking pot shots at the rats with .22s. (The owner's of this small company didn't mind that we visited, although they were somewhat concerned about safety and liability. Apparently we made a favorable impression as responsible young adults, and they were happy with our efforts against the rats. Those river rats get BIG!!!)