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, such as making the target's place of origin undesirable to return to, or that they had nowhere else better to go. (VOY: "Workforce", "Workforce, Part II")