Eradication of rodent species from some offshore islands has proved to be an effective means of conserving native animal communities and restoring natural ecological processes on the islands. As methods of eradication differ for different rodent species, a truthful monitoring method to detect species presence and relative density is essential for a successful eradication programme. This study compared two spatial arrangements (line vs. grid), 5 different baits (chocolate, cheese, soap, wax, oiled wood) and 3 cover types (transparent plastic, wire netting, galvanised iron) on the detection of 2 species of rodents on Browns (Motukorea) Island in June and August.