Like rabbits, Malagasy giant rats live in burrows, which typically consist of a network of tunnels, each around 45 centimetres in diameter and up to five metres long (2). These are occupied by a family group consisting of a monogamous pair, their current offspring and their female offspring from the previous year. Families maintain and defend a territory covering three to four hectares (6). Territory borders are marked with urine, faeces and scent gland deposits. The burrows are not only used for raising offspring, but also for protection against predation and heat during the day and heavy rain during the night (4). Pairs mate for life, but if one mate dies they are normally replaced within a few days or weeks (6). Litters of one or two young are born in the rainy season in late November and early December (5), after a gestation period of 102 to 138 days (4). Young stay within the safety of the burrow for the first four to six weeks before venturing out (4). Male offspring leave their natal territory and are able to breed at one year, if they can establish a territory and attract a mate. Female offspring may remain with their parents for up to two years before they get sexually mature and disperse (4). Males are thought to be monogamous in order to help protect their young from high levels of predation and the contribution of male parental care is assumed to be very high (6).
This nocturnal rodent spends the day within its burrows, emerging at dusk to forage either alone or in pairs on the forest floor (4). The rats are primarily herbivorous, feeding on fallen fruit, seeds and leaves, digging for roots and tubers and stripping bark from saplings (4), although in captivity some have also been observed eating invertebrates (2).