  Non-motile active matter exhibits a wide range of non-equilibrium collective
phenomena yet examples are crucially lacking in the literature. We present a
microscopic model inspired by the bacteria {\it Neisseria Meningitidis} in
which diffusive agents feel intermittent attractive forces. Through a formal
coarse-graining procedure, we show that this truly scalar model of active
matter exhibits the time-reversal-symmetry breaking terms defining the {\it
Active Model B+} class. In particular, we confirm the presence of microphase
separation by solving the kinetic equations numerically. We show that the
switching rate controlling the interactions provides a regulation mechanism
tuning the typical cluster size, e.g. in populations of bacteria interacting
via type IV pili.
