often leading to steady states that are not invariant under time reversal and exhibit macroscopic currents [@Cates2012]. Such currents, or collective motion, have been reported in a variety of systems [@Vicsek2012], including Vicsek particles [@Chate2008], mixtures of microtubules and molecular motors [@Sanchez2012], light-activated colloids [@Palacci2013], Quincke rollers [@Bricard2013; @Karani2019], bacterial colonies [@Zhang2010], sperm cells [@Creppy2015], locusts [@Buhl2006], birds, and fish [@Parrish1997]. The omnipresence of collective motion raises the need to classify various active systems according to common features of their phenomenological behaviour. Marchetti *et al.* [@Marchetti2013] recently introduced two broad universality classes for active systems, “dry" and “wet", comprising particles dominated by friction with their surroundings and long-ranged hydrodynamic interactions, respectively. Each class is expected to be defined by a few, relatively simple model systems, and significant effort has been invested into finding such models. For dry active matter, these include Vicsek-like models [@Vicsek2012; @Chate2020], that describe cases where alignment interactions are dominant, and Active Brownian Particles [@Howse2007; @Romanczuk2012] or Run and Tumble particles [@Schnitzer1993], that describe systems dominated by steric forces randomising their self-propulsion direction either smoothly or in a discontinuous manner. In this work, we study dilute suspensions of motile bacteria that, arguably, play the same role for 