• Black Rat (Rattus rattus)

  • Scientific Name

    Rattus rattus


    The black rat is also known as the 'ship rat' or the roof rat.  The black rat is the smaller of the two main rat species in Australia.  It has a more pointed snout (nose) and this rat has large prominent naked ears.  An adult will be 16-20cm long and weight around 300 grams.  The main feature of this rodent is it's tail.  It is longer than the body length of the animal.  Although known as the 'Black Rat' the colours can vary from agouti to grey to brown, white and black.  

    Their droppings are spindle shaped around 1cm long. 

  • Lifecycle

    The average lifespan of rats in the wild is around 6 months with only about 5% surviving the first 12 months.  Young rats become sexually mature at about 90 days - the male is sexually active at that time after independence is gained from the mother but the female is only active during a 4-6 day estrous cycle. (Mallis) 

    The roof rat gestation period is 20-23 days, the average female will produce on average 5 litters but as high as 9 litters in her life with an average of 6 pups per litter (up to 8).  This means the average female will product around 32-34 offspring.  Pups are blind and helpless, even their external ears are sealed down.  Their eyes only begi to open after 12 days.  The pups wean at around 28 days. 


    The black rat is not a good swimmer but is a graceful and agile climber.  The black rat gets it's name from it's harbourages and nesting habits mainly being in roofs or anywhere up high - usually in roof voids, attics, wall voids and soffits/eaves.  In South East Asia where this rat originates they can be found in trees similar to the way squirrels nest.  In the absence of Norway rats, they will next in underground burrows nearly buildings, under rocks or any other debris. 

    The roof rat will forage around 150 metres from the nest.


    All rodents are 'opportunistic omnivores' - that is; they will eat anything they come across!  Roof rats can eat lush vegetation, berries, fruit, snails and nuts so are less dependent on humans as the Norway Rat.  They must have water on a daily basis and will take from any source they can including the moisture found in food.  They consume around 60ml of water per day, sometimes more in humid environments.