The poultry industry has been facing occasional food scandals due to illegal pesticide application caused by intense lice infestation in Taiwan. The unstable and obsolete taxonomic issues on chewing lice could sometimes lead to misidentification throughout certain regions. The poultry lice fauna in Taiwan has not been systematically studied since Sugimoto's study during the 1920s and 1930s, but one of the lice species bore a misused synonym by Sugimoto, which could lead to further misunderstanding of modern valid species. To fill this century-old research gap and potential misuse of synonymy, a field survey focusing on the current poultry chewing lice fauna and infestation levels was conducted. In our survey, we sampled lice from six different poultry farms by a standardized method via modified handheld vacuum cleaners. The lice were then identified through slide-mounted specimens and DNA sequencing, and their relative infrapopulation on each hen was quantified. Five morphological species of chewing lice were identified to be associated with poultry: Goniocotes gallinae (De Geer, 1778), Lipeurus caponis (Linnaeus, 1758), Menacanthus stramineus (Nitzsch, 1818), Menopon gallinae (Linnaeus, 1758), and one possible incidental straggler, Rallicola cf. ferrisi Emerson, 1955. The previous four species were consistent with Sugimoto’s record, but male genitalia variation existed among a few individuals within M. stramineus, which might resemble cryptic species from this well-known pest. L. caponis is the most dominant species found at all sites, accounting for 76.55% of all 10,763 louse individuals collected since April 2025. This survey also indicated that L. caponis exhibited a seasonal outbreak during summer. As the outbreaks of chewing lice were often observed with a single species (L. caponis), a possible competitive exclusion event might have resulted in this scenario. The incidental infestation of R. ferrisi Emerson, 1955 suggested a potential physical contact between its original wildlife host and the hens, with the most likely association with the watercock (Gallicrex cinerea), a summertime migratory bird. Several pieces of evidence suggested that contamination from wild birds could be a main source of poultry louse infestation in Taiwan, including no louse infestation found in the farms with well-blocking of wild birds, and a positive correlation of the biodiversity index of louse against wild birds. As poultry farms act as an amplified parasitic source, it is worth knowing the ecological impact if there were potential ectoparasitic spillover occurring in wild birds.