Rattus norvegicus is the dominant type of rat in both Europe and North America. — Photo by Anemone Projectors
MY late father, who never ever swore or blasphemed, would occasionally utter an expletive when things he was doing went wrong and would whisper under his breath “Drat!” Only very recently I have found that this expression came into the English language in the 17th century as a mild substitute for ‘God and rat.’
Chinese New Year 2020, for the Year of the Rat, arrived on Jan 25 and it was only coming into land, at night, at Kuching airport that I realised the celebrations ended on Feb 8. It was the resplendent firework displays below that jogged my memory.
Research into Chinese horoscopes has told me that those born in Ratty’s year are good money handlers, who never struggle financially and live organised lives. They never seek praise or recognition and they are renowned for their modesty. Tending to take calculated risks, they succeed in their ventures more often than not. In some religions, ladies pray to rat deities in order to bear children, merely because of this mammal’s fast reproduction rates. Whilst we are all part of ‘the natural world’, I shall channel my energies into three animal species – the brown, the black, and the Malaysian field rats.
Brown rat (Rattus norvegicus)
This species originated in northern China and has spread to all continents apart from Antarctica. The dominant type of rat in both Europe and North America, it has been described as the most successful mammal on our planet living alongside humans. With a coarse, brown, or darkish grey coat of fur, its underparts are slightly lighter shades of these colours. It can grow up to 28cm in body length, to which must be added its tail, which can be up to 20cm long. On average, it may weigh up to 500gm but much depends on seasons of plentiful food supply. Omnivorous, a brown rat will eat almost anything but it has a penchant for grain cereals.
Reproductive notes
In optimum climatic conditions, this rat species can produce four or five litters each year with a litter size of between 10 and 12 babies. There is a gestation period of only 21 days. A breeding polygamous male may produce up to 1,000 rats per annum! Female rats can become pregnant again immediately after giving birth to one litter and can nurse one litter, whilst pregnant with the next. It has been said, that wherever we live in the world a brown rat is within a metre away from us.
There are currently an estimated 120 million rats in the UK; nearly twice as many rats as people.
Taking over our cities?
It has been estimated that there are currently 120 million rats in the UK; nearly twice as many rats as people. This estimate is based on the fact that the UK has a generally milder winter, thus allowing all year reproduction with ever increasing populations of rats in city sewers. Worldwide climate change should see ever increasing numbers of brown rats in our cities as they scour for food sources in our homes, our refuse bins, and those of food outlets, restaurants, coffee shops, and wherever their sensitive noses can detect ‘ripe pickings’.
They gain easy access to our houses through sewers, outlet drainage pipes for washing machines, or by climbing up roof drainage pipes to gnaw through cement and brick walls to gain access to our attics. In the latter case where electricity cables lie, they may even gnaw though the outside of the cable causing us considerable costs in replacement. Feral cats in Kuching certainly perform an important function in controlling neighbourhood rats even if we have the dirty job of picking up rat corpses in our gardens. Like all rat species, brown rats are flea-ridden and thus can transmit numerous diseases.
Black rat (Rattus rattus)
Often referred to as ship rats or house rats, they have the longest tails in the rat kingdom, up to 22cm. Although weighing up to 230gm, they have much smaller body sizes than the brown rat. It is thought that black rats migrated from Southeast Asia, and in particular from Malaysia, to Europe in post glacial times. When the Romans invaded Britain, their black rats literally jumped ships by climbing down moored ropes or even swimming ashore.
In Malaysia, this species explodes in numbers when bamboo plants fruit but generally worldwide they are found in coastal regions, best at home in urban areas, barns, and crop fields. Like the brown rat, they are omnivorous but they prefer fruit and nuts thus feeding essentially on cereals, coconuts, coffee beans, and sugar cane. Great climbers, they choose palm trees and coastal pines in which to build their oval nests, preferably near rivers or reservoirs as they are vast consumers of water.
The most extensive studies of these rats have been carried out in Australia and New Zealand where they have displaced other native rat species. In those countries, the eradication of black rats has been most successful. I have only ever once seen a black rat in Madagascar in a coastal village. In that country, the black rat has outgrown various species of the island’s rats.
Black rats may still be found in the UK in portside locations such as London and Liverpool. It is thought that an explosion in the brown rat population in the 18th century caused a massive decline in the black rat population in the UK. There is little doubt globally that black rats were invaders from moored early explorers and traders’ ships.
Malaysian field rat (Rattus tiomanicus)
This nocturnal and arboreal species is not only found in Malaysia but also in Indonesia, Philippines, and Thailand. A relatively minute species, for its body length is but 1.9cm with a longer tail of 2cm. It weighs up to 150gm. With large, almost naked ears, and flattened, short haired brown fur together with a silvery whitish belly, it should not be easily confused with the rice field rat (Rattus argentiventer).
Its natural habitat is that of primary and secondary rainforests but may very seldom be found in dipterocarp forests and even in our gardens under a heap of palm tree fronds. Oil palm plantation fruits are its favourite food source.
I have only ‘tickled’ the numerous rat species that Malaysia holds for, just in one place, at Mount Kinabalu National Park, in the trek to the summit over 13 species of forest rats have been observed.
Vermin!
This was the shout that my late mother uttered when she saw a brown rat sniffing around at the bottom of the garden and I responded by baiting, setting, and staking into the ground a rat trap. These rats emerged from their warm nests in a decaying compost heap which my parents kept. Suffice to say, at a young age, I became a pretty competent rat trapper without the trap spring ever catching my fingers.
The fear of diseases spread by rats still haunts me. Such diseases include potentially fatal ones, such as the hanta virus pulmonary syndrome and salmonella-like sicknesses and cholera. Today we can rid these inquisitive and invading rodents by using baited cage traps or even plastic covered poisoned bait bags or, better still, plug in an electric rat-repellent device. The last method is safer with animals and children around. Tough rats deserve tough measures!
In whatever way, as individuals, we may view rats let us all rejoice in the New Year of the Rat. I am sure that open houses provided many of us with the sort of hospitality that animal rats would love to have got their incisor teeth into! May we all have a happy, healthy, and prosperous Year of the Rat.