  Living many-body systems often exhibit scale-free collective behavior
reminiscent of thermal critical phenomena. But their mutual interactions are
inevitably retarded due to information processing and delayed actuation. We
numerically investigate the consequences for the finite-size scaling in the
Vicsek model of motile active matter. A growing delay time initially
facilitates but ultimately impedes collective ordering and turns the dynamical
scaling from diffusive to ballistic. It provides an alternative explanation of
swarm traits previously attributed to inertia.
