Pest mites found in grain, flour, and feed warehouses and also on the shelves of business establishments are common in Brazil. This study aimed at describing the mite fauna associated with environmental factors and several production-line environments inside animal feed factories. Mites were collected from: package depositing (PD), rice bran milling machine (RB), corn conveyor belt (CB), soybean silo (SS), pigeon nests (PN), animal product elevator (AP), pellet cooler (PC), and from the roof of an animal feed factory (R). A total of 2401 mites were collected, belonging to 13 species in 12 families, along with Uropodina and the suborder Oribatida. Higher richness was observed for Cheyletidae, and the highest richness was observed in PN and SS. Dermatophagoides farinae was the most abundant species (883 specimens), followed by T. putrescentiae (654) and C. malaccensis (506). In PC, the place with the highest infestation, we observed 36% of total mite populations, followed by CB with 17.5%, and RB and SS, with 14% each. There was no significant correlation among mite infestation, temperature, and relative humidity (RH). The period with the highest abundance was between March and August. The most abundant species in March was D. farinae, and T. putrescentiae was the most abundant in August. From December to February, C. malaccensis was the most predominant species. Thus, this study showed the prevalence of two pest species (D. farinae and T. putrescentiae) in several production-line environments in an animal feed factory and the presence of a potential predator, C. malaccensis.