  We examine the mobility and velocity fluctuations of a driven particle moving
through an active matter bath of self-mobile disks for varied density or area
coverage and varied activity. We show that the driven particle mobility can
exhibit non-monotonic behavior that is correlated with distinct changes in the
spatial-temporal structures that arise in the active media. We demonstrate that
the probe particle velocity distributions exhibit specific features in the
different dynamic regimes, and identify an activity-induced uniform
crystallization that occurs for moderate activity levels and that is distinct
from the previously observed higher activity cluster phase. The velocity
distribution in the cluster phase has telegraph noise characteristics produced
when the probe particle moves alternately through high mobility areas that are
in the gas state and low mobility areas that are in the dense phase. For higher
densities and large activities, the system enters what we characterize as an
active jamming regime. Here the probe particle moves in intermittent jumps or
avalanches which how power-law distributed sizes that are similar to the
avalanche distributions observed for non-active disk systems near the jamming
transition.
