Rats and mice are a serious threat to our health and property. Like all pests, they live in constant search of food and water. Rats are omnivorous and will eat any food that is available in the home and work environment – even protein-based foods such as meat, poultry, eggs and fish. Mice are herbivores, preferring cereals, grains, fruit and vegetables.

Laying down poison in your home or work space can have serious consequences...- Mario Borg

Both species readily invade our living spaces if they find easy access to food and water. Having set up home within the safety of our houses and offices, rats and mice will breed prolifically and within a few months will multiply into hundreds. However, both rats and mice leave plenty of evidence that alert us to their presence.

The most noticeable are their dark brown droppings; you can tell the difference between a rat and mouse dropping from the size – about two centimetres long for rats, and half a centimetre long for mice. In fact, rodent droppings are likely to be your first indication of a possible infestation.

Scratching sounds in soffits and furniture recesses can become audible when the environment is quiet and, if you share your home with cats or dogs, they will quickly alert you to a possible presence.

In Malta, we have three types of rodents: the Brown or Norway Rat (Rattus norvegicus or far tal-kampanja), the Black Rat (Rattus rattus or far iswed), and the domestic mouse (Mus musculus or ġurdien ta’ l-imramma).

The greyish-brown Norway Rat is more appropriately known as the sewer rat because it favours the sanctuary of our sewers where it has no natural predators; they are particularly strong swimmers and can swim up rainwater gutters and even against strong currents in sewer canals.

Their filthy environment means that they carry dangerous and potentially fatal bacteria on their feet and body hair. In fact, passageways that are regularly used by the Norway Rat gradually build up a greasy layer of scum from their bodies. As they rummage through food and scuttle over surfaces, they leave this imperceptible trail of filth which we inadvertently touch and carry to our mouth. Although the Black Rat and mouse live in relatively cleaner environments, their presence in our homes can be equally dangerous to our health.

All three rodent species shed thousands of hairs from their body; they continuously urinate and drop faeces onto our food stores and belongings. Accidental ingestion of food and water containing their body hair or waste is dangerous and potentially fatal.

Some of the diseases and bacteria include Leptospirosis (Weil’s disease) which they also transmit through contamination of water with their urine, as well as salmonella, E. coli, listeria, tuberculosis, brucellosis, and rat-bite fever. The fleas, mites and ticks they carry are equally dangerous and can transmit disease to our pets too. But rats and mice do not only bring with them the risk of contamination; they are also a major cause of serious financial loss – both in the home and work environment.

Rats and mice have strong sharp teeth that grow very quickly. To keep them trimmed back, they continuously gnaw on hard objects such as wood, plastic, and poorly treated concrete. One of their favourite objects to grind is electrical cabling. At best, a rodent will short-circuit your electrics and cause power failure or outage; at worst, they will cause electrical fires that ravage your home or workplace. Insurance companies in many countries have now introduced a policy of no payment if it can be proved that electrical fires were caused by a known infestation of rodents that was ignored.

In Malta, a favourite DIY product against rodents is rat poison. But laying down poison in your home or work space can have serious consequences if you, your children, pets, or employees accidentally ingest it or absorb it through their skin if not washed immediately.

Another disadvantage is that a poisoned rodent may crawl away to die in a secluded area which is most often inaccessible to us. The resulting rotting rodent carcass can create hazardous disease-related conditions as well as produce noxious odours that are difficult to get rid of. There is also the impact on the environment and danger to wildlife since poisoned rodents could contaminate freshwater supplies or even more dangerously could end up in the food chain of wild animals.

Rodent traps are another favourite, but handling live trapped rodents leaves you vulnerable to contamination and bites, while dead rodents harbour fleas that are associated with numerous diseases.

Other modern contraptions include ultrasound repellers that emit sounds inaudible to the human ear but uncomfortable for rodents.

There is no tangible proof that these solutions are effective – ultrasounds are quickly absorbed by physical structures and furniture while rodents also quickly get used to the sound.

There are many preventive measures to mitigate infestation (see below), but because rodents breed so prolifically it is very difficult to eradicate. For the well-being of your family or employees, you should contact a professional pest control company licensed to operate trained personnel and handling appropriate equipment for extermination of rodent infestations.

This company would have the necessary expertise to track down the source of infestation and provide the equipment needed to rid your environment of rats and mice safely and humanely.

Professional handling of the extermination process also means that your pest control company will rid your living or work spaces of dangerous rodent carcasses.

Mario Borg is general manager of a pest control company.

whats.bugging.u@gmail.com

What you can do

• Cover securely your rainwater and waste water U-traps (gullies) with mesh and seal up sewer slabs so that the Norway Rat will find no openings above ground.

• Store boxes containing paper, clothing or wool in the basement provide excellent nesting for the Black Rat and domestic mouse, so this should be done on shelving.

• Always keep the kitchen clean; wiping down all food surfaces and appliances is a sine-qua-non. Make sure your garbage bins have well-fitting and secure lids.

• Don’t leave pet food out overnight and sweep up spilt birdseed from around your birdcages. Regularly clean out aviaries and animal pens. Seal up your pet foods in plastic containers – rats and mice will rip through packaging in no time. If you need to stockpile animal feed store it on shelving and rotate its use regularly to ensure that old stock is used first: rodents are also extremely wary of change and will wait before trying out the food source.

• Seal up all cereals or grains in plastic or glass containers and refrigerate tubers such as potatoes and carrots.

• If you have fruit trees in your garden, collect the windfalls regularly. Do not put leftover meat, poultry, fish, animal and fish bones or dairy products in the compost bin and make sure you regularly turn over your compost and lime it properly.

• Plant bushes away from the walls of your house. Creepers may look beautiful, but they provide rodents with very easy access to your house. If you have trees close to your house, prune them back regularly and make sure your air vents are sealed up.

• Repair all plumbing leaks to prevent easy access to good water. When not in use, cover up fresh water pools and outdoor jacuzzis.

• Last but not least do put down the lid of the toilet bowl after use, as rats are occasionally known to emerge from the sewer pipe through the toilet water bowl, especially at ground level.