Odd caucuses are nothing new. In 1949, more than a dozen House Republicans formed the Chowder and Marching Society in opposition to veterans bonuses that they felt would cost the government too much, which eventually grew into a legislative think tank of sorts for the party.

The proliferation of caucus groups in recent years has led to the formation of some groups that wouldn't typically be associated with legislative work. In 2013, Representatives Aaron Schock, R-Ill., and Tulsi Gabbard, D-Hawaii, formed the Congressional Future Caucus, dedicated to all things millennial.

Today, the Congressional Future Caucus is hardly alone. There's also a Congressional Soccer Caucus. Then there's the Congressional Bourbon Caucus, chaired by two House members from—naturally—Kentucky, Democrat John Yarmuth and Republican Brett Guthrie. Of course, neither of the Bourbon Caucus cochairs sits on the Congressional Kidney Caucus.

There's also the Congressional Bike Caucus, headed by none other than Portland, Oregon-based Representative Earl Blumenauer, a Democrat who has a penchant for wearing neon-colored bicycle pins on his lapel. His colleague, Representative Peter DeFazio, D-Ore., cochairs the Congressional Small Brewers Caucus alongside Representative Jim Gerlach, R-Pa.

The Civility Caucus, which seems out of place in modern Washington, was retooled in the aftermath of the Tucson, Arizona, shootings to promote kindlier discourse between members of both parties and do away with the kind of vitriol that can take over committee hearings and floor speeches.

A majority of caucuses are devoted to U.S. relations with individual foreign countries (for example, the Congressional Azerbaijan Caucus and the Congressional Friends of Liechtenstein Caucus). Another major chunk of the groups are dedicated to a particular disease or medical issue, including Parkinson's, cystic fibrosis, Down syndrome, brain injury, and dyslexia. Another eight caucuses are devoted to food and drink, ranging from the aforementioned Bourbon Caucus to the Congressional Caucus on Wild Salmon, the Congressional Wine Caucus, and the Congressional Rice Caucus. All of which, presumably, occasionally butt heads with the Congressional Food Safety Caucus—here's looking at you, Congressional Shellfish Caucus.

And there is some overlap as well. Incoming freshmen members should learn early to differentiate between the the Congressional Hispanic Caucus and the Congressional Hispanic Conference, which are run by Democrats and Republicans, respectively.

On average, members of the House belong to 34 of these caucuses, according to Congressional Research Service data, while senators typically belong to about 18 of them (there are far fewer caucuses in the Senate than in the House). Of course, some members, like overachieving high school students seeking an advantage on college applications, belong to many more caucuses. At least one House member signed up for 132 of them in the last Congress.