What new activities do the boys come up with to avoid homesickness and wanting to go home?

The boys quit playing pirates for awhile and played Indians.

After the meal they felt rusty, and stiff-jointed, and a little homesick once more. Tom saw the signs, and fell to cheering up the pirates as well as he could. But they cared nothing for marbles, or circus, or swimming, or anything. He reminded them of the imposing secret, and raised a ray of cheer. While it lasted, he got them interested in a new device. This was to knock off being pirates, for a while, and be Indians for a change. They were attracted by this idea; so it was not long before they were stripped, and striped from head to heel with black mud, like so many zebras—all of them chiefs, of course—and then they went tearing through the woods to attack an English settlement.

By and by they separated into three hostile tribes, and darted upon each other from ambush with dreadful warwhoops, and killed and scalped each other by thousands. It was a gory day. Consequently it was an extremely satisfactory one.