They have produced "reddish-brown stalactites of rust [hanging] down as much as several feet, looking like long needle-like icicles", as Ballard has put it. The formations, which Ballard dubbed "rusticles", are extremely fragile and disintegrate in a cloud of particles if touched.[119] The bacteria consume the iron in the hull, oxidising it and leaving rust particles behind as a waste product. To protect themselves from the seawater, they secrete an acidic viscous slime that flows where gravity takes it, carrying ferric oxides and hydroxides.