Ants display a diversity of social structures reflected by differences in caste, nest, and colony organization. Previous research has shown that highly eusocial insects (Hymenoptera) exhibit genome-wide signatures of relaxed selection due to their smaller effective population sizes. However, it is unknown how colony structure itself may shape the evolution of eusocial species though its effects on the worker caste. Worker ants typically either produce only male offspring or are sterile, thus worker traits evolve primarily through kin selection. Here, we predict that workers should be subject to selective forces of varying strength according to the social context of their species. This follows from kin selection theory, which predicts that kin selection should be more effective in contexts of high relatedness between the altruist (worker) and beneficiary (nestmates), such as in single-queen (monogyne) contexts. Alternatively, in species with many queens and low intra-nest relatedness, such as polygyne or unicolonial species, kin selection should be less effective, ie. more relaxed on genes controlling worker traits. We show that worker-specific genes in unicolonial species show significantly more relaxed selection compared to queen-specific or non-differentially expressed genes. Interestingly, we also find that levels of relaxed selection in worker genes and average queen number per nest do not have a strong correlation in species with only several or varying numbers of queens per nest. This may point to possible compensatory mechanisms present in these contexts to counteract relaxed selection in workers, or that these predicted patterns are too subtle to be detected with current methods, highlighting areas of future study.