Nile Rats
Nile Rats
Arvicanthis niloticus
Alternative Names: Unstriped Nile Rat, Arvicanthus Bush Rat (its previous name), Kasu or Kusu rat.
About the Nile rat:
Although like many species there is confusion regarding their taxonomy it is generally agreed that there are five species. Of these five species only Arvicanthis niloticus is commonly seen in captivity. Arvicanthis niloticus is common in Africa where it and the other four species in the genus originate.
In the wild it inhabits scrubby regions, forests and grasslands showing that it is a highly adaptable species.
The species is extremely sociable and should never be kept individually. If you do not wish to breed either two males or two females will happily live together with out quarrels. It should be noted however that established adult females can be aggressive to other older females and so introductions should ideally be done when the animal is young or done with utmost caution!
The species is often struck by massive population crashes after a sudden and rapid increase in their numbers in a given area. These overwhelming populations simply exhausting food supplies and effectively starve themselves, cause this drop in numbers. The population always stabilises itself again once this dip has occurred.
They are a reasonably simple species to keep and breed and although not aggressive towards the handler, they are skittish and difficult to handle.
They are a clean species that do not produce as strong an odour as the domestic fancy rat but will still require regular replacement of all the substrate in the enclosure.
They are rounded in appearance and are a dark brown agouti ticked with black and yellow. They Nile rats fur is not soft but rather course, more like that of a male fancy rat. They can jump surprisingly high given their rotund body shape. Many Niles show an obvious dorsal stripe running the length of their backs. They have a tail, which is slightly shorter in length than is their body and is mostly naked. Their facial features are more akin to mice than to rats and this probably explains why they are some times referred to as ‘unstriped grass mice’. They Nile rat is neither nocturnal nor diurnal but is instead crepuscular, showing periods of frenetic activity at intervals throughout the day but particularly at dawn and dusk.
Enclosure:
In captivity they require a large enclosure such as a four-foot glass tank with a tightly fitting lid or a chinchilla type cage with a deep base. They will chew and destroy anything not made of metal within their enclosure so it is very important to ensure that anything that you give them to play with is made of a non toxic, safe material. Avoid brittle plastic items and branches from poisonous trees or those sprayed with any form of insecticide. A wooden nest box is a good addition to the cage but will need replacing regularly when it begins to crumble following the attentions of the Nile rat’s teeth. If you have just introduced a new pair then give them a chance to establish their status quo before you give them a nest box. Newly introduced pairs may fight and if the dominant animal corners the submissive individual in the back if a nest box it will not be able to get away and serious injury could result. Fresh hay should always be available to the Nile rats and they will both eat this and use it as bedding so make sure that it is of a good quality. Wheels are not really necessary but if you decide to use one please make sure that it is a solid one as legs and tails are too easily broken should they slip between the spokes of an open type wheel.
Diet:
Nile rats are generally herbivorous in their feeding habits and this has led their persecution in their native Africa where they consume seeds, shoots and cultivated crops.
A good captive diet consists of a mixture of small seeds, a good quality guinea pig mixture or pellets, grass, broccoli, dandelion, cabbage and carrots. A small amount of BogenaÔ or OrluxÔ soft bill food, which contains dried insects and wild berries. Nile rats do not drink a particularly large amount but none the less, they should always have access to fresh drinking water contained in a water bottle – not a bowl.
Breeding:
In captivity the Nile rat will breed thought the year if kept at an ambient temperature. Females do not have seasons unlike like many small animals and are instead spontaneous ovulators accepting a male at any time.
Litter sizes generally consist of between four and six youngsters although larger litters do occur. The gestation period is between twenty and twenty-four days depending on the size of the litter that the female is carrying. The female will have a post parturition oestrus and will mate again very soon after giving birth. This causes a considerable amount of physical stress to the female who will be pregnant and lactating at once. To avoid back to back litters, remove the male before she gives birth and reintroduce them at a later date when the female has had a month away from her young and has had chance to regain any condition she has lost. Nile rats are born semi-precocial rather than entirely dependant, as are domestic rats. If the male has been left in the tank he will not harm the babies and sometimes even assist the female in keeping the babies warm and clean. The babies open their eyes with in a few days of birth and are bumbling around the enclosure by two weeks of age. The babies are weaned at twenty-one days of age and hit sexual maturity at three months.
