Latency measures indicate new place neophobia in Rattus species

Latency to enter an unfamiliar wooden alley from the home cage was recorded on successive daily trials in several populations of domestic rats. All groups showed a decline in latency over days suggesting an initial neophobia. Latencies for individual rats on Trial 1 showed a bimodal distribution in most groups, reflecting mild or intense avoidance of the unfamiliar area. Earlier reports of new place reactions in wild Rattus suggesting an immediate neophilic reaction to a novel area may have overlooked initial hesitations to enter the area because latency measures were not used systematically.