Rats, mice, and mess: Unveiling rodent residents in selected male and female halls at the University of Ibadan

Rodents are key commensals in human settlements, posing structural, economic, and public health risks. This study assessed species composition, abundance, and diversity of commensal rodents in selected male and female halls of residence at the University of Ibadan, Nigeria. Three male and three female hostels were purposively selected; in each hall, 27 traps (three rooms per floor across three floors) were set for three nights weekly over eight weeks. By morphological characterization, captured specimens were identified and analyzed for frequency, abundance, and diversity using SPSS and PAST. Three commensal species — Rattus rattus (black rat), Rattus norvegicus (brown rat), and Mus sp. (house mouse) — were recorded across halls. A total of 79 commensal rodent species were captured; Mastomys natalensis was not detected. Female halls accounted for 77.2% of total captures, exhibiting higher overall abundance and slightly greater species-level diversity metrics (Shannon H: Mus sp. 1.073; R. norvegicus 1.072; R. rattus 1.058) compared with male halls (R. rattus Shannon H 1.011). Significant variation in species abundance was observed within individual halls (chi-square, p < 0.05). Dominance indices indicated skewed assemblages dominated by one or two species per hall. Physical inspections revealed multiple structural and sanitary features conducive to rodent entry and persistence (cracks, unsealed vents, exposed food, inadequate waste management). The predominance of commensal rats and mice in student hostels underscores elevated potential for property damage, contamination, and zoonotic pathogen transmission. Regular monitoring, targeted structural repairs, improved sanitation, and integrated pest management strategies are recommended to mitigate rodent-associated risks in university residential environments.