  We show, based on a theoretical model, how inertia plays a pivotal role in
the survival dynamics of a prey swarm while chased by a predator. With the
varying mass of the prey and predator, diverse escape patterns emerge, such as
circling, chasing, maneuvering, dividing into subgroups, and merging into a
unitary group, similar to the escape trajectories observed in nature. Moreover,
we find a transition from non-survival to survival of the prey swarm with
increasing predator mass. The transition regime is also sensitive to the
variation in prey mass. Further, the analysis of the prey group survival as a
function of predator-to-prey mass ratio unveils the existence of three distinct
regimes: (i) frequent chase and capture leading to the non-survival of the prey
swarm, (ii) an intermediate regime where competition between pursuit and
capture occurs, resembling an arms race, and (iii) the survival regime without
the capture of prey. Interestingly, our study demonstrates the existence of a
favourable predator-prey mass ratio for efficient predation, which corroborates
with the field studies.
