Their ships used warp technology and tractor beams, the Quarren also used subspace mines. Quarren systems required a high level of supervision and involved little automation, which was unique for a warp-capable species. The Quarren made use of a multi-species workforce, and extended full rights and protection to non-Quarren employees.
Unknown to most Quarren, some workers were acquired by less scrupulous employers through abduction because their homeworld suffered from a severe manpower shortage. These criminal Quarren made use of memory alteration to make their captured workers more productive and less likely to escape. (VOY: "Workforce", "Workforce, Part II")