Rats are medium-sized, long-tailed rodents, varying in species from the superfamily Muroidea. These animals are classified as pests, invasive species, model organisms for scientific research, pets, odour detectors of landmines and tuberculosis, and even dietary staple in some cultures. Rats are present in all cultures and continents, except Antarctica due to its hostile climate. We researched and summarised the most important data to present coherently in this article. Our aim is to provide all the necessary facts and behaviours, that you need to be aware of and recognise when dealing with rats.
Table of Contents
- What Types of Rats Infest Homes?
- What Do Rats Look Like?
- What Do Rats Eat?
- Where Do Rats Live?
- Are Rats a Health Hazard?
- What Other Damage Can Rats Cause?
- How to Spot Rat Infestation?
- How to Prevent Rat Infestation?
- How to Get Rid of Rats?
The 'true-rats' are the most common house intruders – the black rat (Rattus rattus, also known as the "attic rat") and the brown rat (Rattus norvegicus, also known as the "Norway rat"). These pests infest any kind of premises seeking shelter from weather conditions. Black rats specifically are considered the world's most notorious invasive species.
Rats are usually distinguished by other rodents like mice by their size. Exact size, colour, tail length, fur texture etc. vary between species. However, the two most common nuisances are easy to differentiate.
- The Black Rat has a more pointed nose, is generally smaller (12 to 18 cm) and with lighter fur coat varying from black to light brown. Its tail is also almost as long as its body.
- The Brown Rat can weigh as twice much as the black rat. Its size varies between 20 and 25cm, while its tail is around 18 to 25cm. Their fur is coarse, usually brown to dark grey with greyish-brown undertones.
Rats are nocturnal omnivorous animals, thus they tend to feed at night. They can survive on any natural material, animal or plant-derived. However, they prefer grains, seeds, nuts or any food provided for animals. Meat is also part of their diet – any animal corpses including other rats. On average, they consume 10% of their body weight, hence between 15 to 30 grams per day plus 15 millilitres of water.
Rats are burrowing animals - this is why having rats in the garden is a common problem for those who live in rural areas. Rats create nests of any materials on hand – dry grass, leaves, paper etc. They can live in holes in the soil outside and virtually anywhere inside or around properties where there's food, water and shelter.
In cities and homes, they are usually found in sewers, drains, basements, attics, wall cavities, under floorboards and compost heaps.
Rats are commonly known for diseases and virus carriers. However, the Centre for Disease Control lists only about a dozen diseases transmitted directly by rodents, of which even fewer can be spread in Europe and the United States. Some of these include haemorrhagic fever with renal syndrome, hantavirus pulmonary syndrome, rat-bite fever, salmonella and others. You can get infected by coming in contact with rat urine, faeces or getting bitten by a diseased rat.
The word “rodent” is derived from the Latin "rodere" which means “to gnaw”, a well-deserved name for their unstoppable nature of chewing on anything. An unnoticed or ignored rat or mice infestation can actually lead to substantial destruction of property, woodwork, water pipes, electric cables, paper, and textiles, and in the worst cases cause structural damage.
Rats are generally shyer than mice, so spotting them while scavenging might be near impossible unless you are harbouring a substantial infestation. However, there are other tell-tale signs you can look for. The first step is to look for any indicators of rat presence. Such indicators include:
- Rat droppings – Usually concentrated in specific areas such as kitchen cabinets, cupboards, drawers, bins. This occurs due to rats' tendency to produce up to 40 droppings per night, usually in places they feed. Droppings resemble large grains of rice – dark brown coloured and spindle-shaped.
- Burrowing or scratching noises – Black rats are famous climbers, for which they are also known as roof rats. They can easily access roofs, attics, upper floors, lofts, so scratching noises often suggest their presence. Brown rats on the other side may produce rather burrowing or grinding noises as they move about and nest.
- Urine pools or urine trails – Rats are known for their weak bladders, thus they are prone to dribbling urine wherever they go.
- Gnaw and nibble marks – Wood is their favourite, but they will gnaw on anything that's available. This includes food boxes & containers, food products, cables and others. Sometimes you might not find gnaw marks on wood, but sawdust or wood chips might be found near baseboards, cabinets, door and bed frames.
- Rat nests – Nests are created in small, private spaces, usually far from people. These may be in unused closet spaces, basements, between ceilings and floors, inside walls, attics, boxes, dressers, behind appliances and etc.
- Tracks – Such as footprints or tail marks, rats drag their tails usually leaving marks. If you are unsure or unable to identify the marks, flash a light on the suspicious area.
Ensuring that your property is free of food, water sources (such as leaking drainage systems) and harbourage sites might keep you rat free. However, if you want to completely prevent any rat infestations in the future, you can take it to the next level with these methods:
- Keep your garden clean and tidy;
- Pick up any fallen fruits immediately;
- Keep rubbish in proper containers with the lid on;
- Compost heaps must be placed over a galvanised steel mesh with a tightly closed lid;
- Rat proofing your property with special non-chewable materials;
Rats are very difficult to get completely rid of. Setting traps or just placing rat poison isn't sufficient, as rats have a high breeding rate. Chances are if there are signs of rodent activity, there is also breeding activity happening that you are unable to witness. Battling rats is safe and efficient only when handled by a professional rat exterminator.
Infestation Facts on Other Household Pests
- Ant Infestation
- Bed Bugs Infestation
- Cockroaches Infestation
- Fleas Infestation
