A squad was a military unit, usually consisting of eight to fourteen infantry soldiers. In many militaries, it is the lowest and most basic formation.
In 2153, a squad of more than sixteen Military Assault Command Operations soldiers were assigned to the NX-class Enterprise NX-01 for the mission into the Delphic Expanse (ENT: "The Expanse", "The Xindi") In 2154, Captain Jonathan Archer suggested to Captain Erika Hernandez that she have a squad aboard Columbia NX-02. (ENT: "Home")
Klingon Birds-of-Prey contain at least one squad, which consist of at least five soldiers. (ENT: "Borderland")
When Jadzia Dax was kidnapped by the Klaestron in 2369, and the crew of Deep Space 9 was attempting to prevent the kidnappers from leaving the station Commander Benjamin Sisko ordered all of the docking ring airlocks sealed, and Odo ordered Security to send all duty squads to the docking ring and commence an "immediate inward sweep, levels sixteen through twenty one." (DS9: "Dax")