Mosquitoes, for instance. They are never invited, but in Florida, they almost always show up for the party.

And gulls. Perhaps the ultimate freeloaders if you are near a large body of water, gulls beg for food and get uncomfortably close on too many occasions.

Then there’s your neighbor’s dog. He knows you, and he is friendly — maybe too friendly when he smells whatever you have got on the grill.

But if you live by a golf course, the worst culprit for just barging in unannounced is the poorly aimed golf ball. The stray golf ball arrives very quickly and bounces around among your guests — sometimes actually hurting them — before he settles in.