Foraging behaviours did not differ across sexes. However, light had opposing effects on the amount of time spent in the central chamber – females tended to spend more time in the central chamber under illumination (but not significantly so), while males spent significantly less time there under illumination. Male and female ship rats are unlikely to show dichotomous behaviour due to sexual dimorphisms – males and females show little variation in colouration, weaponry, ornamentation, or size – they are equally conspicuous under illumination. However, males hold larger home ranges than females58 and may therefore encounter predators more often59 potentially selecting for more cautious movement. Females hold smaller ranges but may acquire a more detailed knowledge of that range60, perhaps in preparation for the breeding season where they are more sedentary61 and reduced mobility requires them to have precise information on local foraging, denning and sheltering opportunities; the need for local knowledge may have led non-breeding females to exploit light as a way of rapidly advancing their knowledge of a local but unfamiliar patch of habitat. The female strategy may change once she is pregnant (i.e. heavier and less agile), due to greater predation risk62. Further research on seasonal changes in antipredator behaviour would be useful.