The ones found in our urban areas and around our homes are called introduced rats, which came out to Australia in the early days of settlement. They usually came aboard ships from Europe. There are two main ones, the black rat and the brown rat. When my son was about 11 years old he had a pet white rat, which was probably a rattus rattus. He loved her and called her Adidas after his favourite brand of sneakers.
Unfortunately, we lived close to the bush in North Queensland then and one day we found a very large python trying to get into the house, probably to get Adidas. It was on the top step just outside our back door. We took Adidas back to the pet shop, and we used to visit her there sometimes after school. She must have enjoyed our place because somehow she managed to get pregnant and had a litter of little grey baby rats one day when we visited her.
Black rat The black rat is commonly called the ship rat. Its scientific name is Rattus rattus. These rats are cute and have long tails but they become a problem because they breed often and have lots of babies. They also like to move into houses and eat human food and dog and cat food. They can contaminate food and people can get sick from germs. Even though they are called black rats, they are mostly greyish brown on their head and back and have a pale coloured belly. I caught a photo with my wildlife camera of a black rat on my deck in Brisbane coming for a drink of water. I have a large python living in the yard so I think it keeps the rats under control.
Brown rat The brown rat is commonly called the sewer rat or Norway rat. They also snuck aboard ships coming out from England and other places in the early days. Their scientific name is Rattus norvegicus. The brown rat also likes to be comfortable and moves into houses and breeds a lot. They are a problem because they can chew through wires in our homes and cause diseases. Brown rats have brown fur and pale belly.
These two rats are the ones you will most likely see around towns and cities.
I was very lucky years ago to be involved with someone researching zoonotic diseases of rats and I went on many live rat-catching expeditions in North and Far North Queensland, so I got to meet a lot of these native rats.
There are lots of native rats in Australia, but they are very secretive and live in the bush so you won't see them very often. The native rats live on cane farms, tropical woodlands, rainforests, islands, beaches, mountains and swamps. They try and stay away from people and cities, as they are very shy. Most native rats, (except the water rat) are nocturnal which means they come out at night and sleep during the day. Sometimes you might see them if you are camping in the rain forest or bush at night.
One of the native rats is the water rat. It is a beautiful shy rat, which lives along drainage systems from highland lakes to rivers, lagoons, swamps sea shores, river banks, estuaries, mangroves, wharves, lakes, dams and creeks. An adult water rat is about the size of a small cat. Their common name is Rakali and their scientific name is Hydromys chrysogaster.
Water rats have a beautiful fur coat, which is brown tipped with golden yellow on the back, and beautifully tipped with the same golden colour on the flanks and belly. Years ago these rats were hunted for their fur, which was used to make fur pelts, which were exported to South Africa and made into fur coats. They are now protected so no one can hurt them anymore. The Government made the rakali a protected species all over Australia in the 1940s.
The water rat has a long tail, which is white on the tip, and webbed feet. He is an excellent swimmer and uses his hind feet as paddles, to propel him speedily through the water.
He is a shy creature who hides during the day and comes out under the cover of darkness to hunt for food, although water rats are active during the day and night. They are very stealthy and move silently over the rocks and often steal fishermen's bait or even his catch of fish sometimes. I have seen water rats on the breakwater in Townsville.
They eat mussels, fish, frogs, snails, yabbies' and chickens. They are very smart and have been observed collecting mussels and leaving them out in the hot sun to open so they can eat them later. They live in nests they build in a burrow near the water's edge.
Water rats are very vulnerable. Feral cats, foxes and enclosed crayfish traps kill many. They also lose their habitat when creeks and riverbanks are cleared and swamps drained. I found a dead one in Cabbage Tree Creek near where in I live in Brisbane one day. I don't know what killed it.
They are good for farmers because they eat snails that live in ponds that can spread parasites to farm animals and make them sick. Rural property owners and those living on the fringes of the bush can also benefit from rakali populations, particularly in times of mice and rat plagues because the rakali will eat the introduced mice and rats.
Water rats have also learned how to kill and eat introduced toxic cane toads. They have worked out how to avoid getting poisoned by the toads by flipping them over on their backs and eating the parts without any poison glands.
They have also helped the environment in Tasmania by eating the Northern Pacific Seastar, which came in the ballast water of ships from Japan. The Seastar have been very bad for the environment.
The bush rat of Eastern Australia is the most common native rat and is found throughout closed forests and heathland areas. It is a secretive rat seldom seen by people because it likes living in moist dark areas. The scientific name for the bush rat is Rattus fuscipes.
It is a nocturnal animal and eats lots of different things including fruits, insects, seeds, spiders, fungi and plant material.
You can tell the difference between a native bush rat and an introduced black rat because the tail of the native rat is shorter than its body and the ears are rounder. Introduced rats have longer tails than their body and they don't have much hair on their tails.
The swamp rat is another native rat. Its scientific name is Rattus lutreolus. It also has a much shorter tail than the rest of its body. Swamp rats are shy and feed on native plants.
Mosaic tailed rats
Another fascinating group of native rats is the mosaic-tailed rats. There are two types in this group of rats.
Giant naked tailed rat
The giant naked tailed rat, sometimes called the coconut rat is thought to have caught a ride on a floating log to the Torres Strait from New Guinea. The scientific name for this rat is Uromys caudimaculatus, but it has lots of other names including giant mosaic tailed rat, coconut rat, Cape York Uromys, giant white tailed rat and giant naked tailed rat.
Uromys caudimaculatus, Giant white tailed rat. Qld Museum photo
It is a large, aggressive rat, which lives in the rainforest and near beaches and secondary woodland adjoining rainforest in North Queensland.
You can sometimes hear the coconut rat gnawing on nuts and fruits if you are camping in an area where it lives. It also loves to eat coconuts and its strong teeth can chew right through the husk and leave a neat hole.
I've seen these rats when I went bushwalking on Hinchinbrook Island years ago. Some campers have had their cans of beer stolen by these large rats. Their teeth are so strong, they can chew through the can, open it and drink the beer. I've heard they love Carlton Draft. They had to put big metal containers on Hinchinbrook Island for people to put their food into to stop the rats from getting it.
The water rat and the large coconut rat both growl when threatened in a low throaty voice, which can be quite frightening, but they don't hurt people because they run away.
Small Mosaic tailed rat
There are two species of small mosaic-tailed rats. The mosaic-tailed rats are called that because their tails look like mosaic tiles you can have in your bathroom.
One of these is called the Fawn footed mosaic tailed rat. Its scientific name is Melomys cervinipes. These rats are small and weigh about 70 grams. They are shy and gentle rats. The other one is the Grassland rat Melody's burtoni. They are arboreal which means they are good climbers and they are also nocturnal and come out at night. Some of them annoy cane farmers because they climb up and eat the cane stalks.
They live in the rainforest and moist lantana, bracken and creek verges. They are vulnerable in areas where there are cats and where land is being cleared.
These are just some of the native rats that live here in Australia, and some of the differences between the common introduced rats and the less common native rats. I hope the more people know about our beautiful native rats, the more they can grow to like them.
Fawn footed melomys Qld museum Gary Cranitch photo