From Diary of a Wimpy Catholic:
There was a small town that was overrun by wild squirrels. The town leaders had a meeting to decide how to get rid of them. First, the Lutheran pastor spoke and said that his church was prepared to round up all of the squirrels, take them out to the country, and admonish them for their frivolity. The pastor was certain that the squirrels would not return. The Lutheran congregation did as they promised, but, the next day the squirrels were all back and wreaking havoc in the town. Next, the town rabbi offered to round up the squirrels, take them out to the country, and, make them feel guilty for the problems they caused. He was sure that the squirrels would not return. The rabbi did as he said, but, the next day the squirrels returned and were even more bold and destructive. Finally, the Catholic priest offered to round up the squirrels, take them out to the country and make them all members of his parish. The priest did as he said, and now the squirrels only come back to the town on Easter and Christmas.