Succah-hopping is an activity where kids go around visiting a bunch of different succot in their community. It usually takes place on the first day of Yomtov or on Shabbat Chol Hamo'ed. At each stop there are candies, games, divrei Torah etc. Succah-hopping is big in the United States, less so in Britain and just getting started in Israel thanks to American immigrants.
Interesting, this innocuous social activity has a history and a theory. It was apparently invented by Shraga Feivel Mendolowitz (1886-1948), who was a pioneer of Jewish education and outreach in the US. It was intended for students at the Torah Umesorah community day schools which Mendolowitz headed, that were open on Chol Hamo'ed. Some of the students were not observant and didn't have a succah at home, so they'd make class trips to see people's succot and take part in the mitzvah.
At some point it morphed from a school activity for the less-affiliated to a social activity on Yomtov. The idea of sharing, community building and unity that Succot embodies remains. As the Talmud says, "Would that all of Israel could sit in one succah (Succah 27b).