Round white balls

An elderly lady from a remote little town went to one of Philadelphia's most fashionable suburbs to visit her niece
and husband. Nearby was a very well known golf course.

On the second afternoon of her visit, the elderly lady went for a stroll. Upon her return, the young niece asked, "Well, Auntie, did you enjoy yourself?"

"Oh, yes, indeed," said Auntie, beaming. "Before I had walked very far, I came to some beautiful rolling fields.
There seemed to be a number of people about, mostly men. Some of them kept shouting at me in a very eccentric manner, but I took no notice. There were four men who followed me
for some time, uttering curious excited barking sounds. Naturally, I ignored them, too. Oh, by the way," she added, as she held out her hands, "I found a number of these
curious little round white balls, so I picked them all up and brought them home hoping you could explain what they're all about."