Behavior of the Wild Rat

Nearly all wild rats are omnivorous, although this certainly varies among the many different species. For example, in the subfamily Murinae, which includes Old World rats and mice, dietary preferences range from fruits, nuts, fungi and roots to arthropods, small birds, reptiles and mussels. Members of Otomyinae, which contains the whistling rats and vlei rats, rely heavily on grasses, bark, seeds and berries, but will occasionally take insects. Wood rats (Neotoma spp.) vary greatly in their diets, although they are largely herbivorous.

Wild rats can be either arboreal or terrestrial within various types of habitats. The Turner Island wood rat, for example, lives in low deserts or on the edge of forests. Members of the subfamily Tylomyinae are arboreal; their hind feet have even evolved to help them climb more efficiently. Tylomyines live in tropical evergreen or semi-deciduous forests. The odd-looking crested rat (Lophiomyinae) inhabits the mountain forests of eastern Africa. These large rats are slow-moving arboreal rats.

Like with other behavioral features, communication varies greatly between rat species. The aggressive Norway rat (Rattus norvegicus) uses vocal cues as well as body language when communicating with conspecifics. The roof rat (Rattus rattus) is more vocal and uses a variety of squeaks. These rodents also leave trails of oil smears to mark their territory. Tylomines rely heavily on their arsenal of sounds when communicating in a variety of scenarios.

Although this too varies greatly, most rats tend to be nocturnal rather than diurnal or crepuscular. The Angoni vlei rat (Otomys angoniensis) is an example of a primarily diurnal rat. Some rats are solitary creatures while others live in either large or small groups. Roof rats live in groups of several males and females. Norway rats often are found in large packs. Most other species tend to be solitary or live in small family groups.