OK, we had some great fun yesterday in the comments with lots of creative ideas. A few were actually zeroing in on the correct answer. The man was holding ferrets and was a professional rat catcher. In the early 1900 diseases like plague were still a concern, so people went to great lengths to control rats and other rodents. Rat catchers were hired by individuals and businesses to clear the rats out of buildings. Ferrets were used, as were some small dogs, to root out pesky rodents.
Now for today's picture . . . what is this man's job?