Sticky mine

Sticky mines were a type of explosive device. Corporal Purpruff of the Alliance to Restore the Republic's Special Forces was equipped with a sticky mine when she traveled to the planet Hoth while scouting for a new location for the Alliance's headquarters. After discovering huge subterranean caverns on Hoth, the corporal tested their structural stability by attaching a sticky mine to a stalactite and detonating it; however, the stalactite did not even shudder during the explosion. Purpruff later included the results of this test as part of a report on Hoth she submitted, which ultimately ended up being included in the Rebel Files, a collection of physical records documenting the history of the Alliance.

Behind the scenes
Sticky mines were first mentioned in the 2017 reference book Star Wars: The Rebel Files, which was written by Daniel Wallace.