In this paper, we report on a particularly impressive feature of dusty plasma instabilities where moving bright plasma spots (plasmoids) appear in between the electrodes of a low-pressure capacitively-coupled rf discharge (ccrf). These plasmoids show complex behaviors like mutual interactions consisting in their merging or splitting. The interest of this study is beyond the field of dusty plasmas as well-delimited regions of enhanced emission are observed in many different kinds of plasmas (for example at atmospheric pressure in dielectric barrier discharges (DBDs).