Black rats (Rattus rattus) adapt to a wide range of habitats. In urban areas they are found around docks, warehouses, residential buildings where they use their agility (they are excellent climbers) to exploit environments inaccessible to the less nimble brown rats.
They are also found in agricultural areas, such as in barns and crop fields. In urban areas they prefer to live in dry upper levels of buildings, so they are commonly found in wall cavities and false ceilings. Rats will eat nearly any type of food, but they prefer high-quality foods such as meat and fresh grain.
Rats require 1/2 to 1 fluid ounce of water daily when feeding on dry food so are often found close to water sources. Rats have keen taste, hearing and sense of smell. They will climb to find food or shelter, and they can gain entrance to a building through any opening larger than 1/2 inch across. The black rat, along with the brown rat, is one of the most widespread animal species in the world.
Salmonella – carried by all rodents. This can cause mild to severe gastric illness.
Trichinosis – Pork roundworm. Initially the worm lodges in the intestines, but the larvae may invade the muscles to form cysts that are often resistant to drug treatment.
Rat Bite Fever – Murine Typhus spread by lice on the animal, they die of it, but not before they have passed it on.
Weil’s Disease – Leptospiral Jaundice (Leptospirosis). Symptoms are initially flu like, with a severe persistent headache; if someone exhibiting these symptoms has been in an area where there are rats, then they should seek immediate medical advice as this potentially fatal condition can cause damage to the liver and kidneys and needs early treatment.
Poor sanitation and the presence of rubbish help rats to survive in residential areas. Good sanitation will effectively limit the number of rats that can survive in and around any building This involves proper storage and handling of food materials and refuse, and elimination of rodent shelter (harbourage).
Outside dog pens must be properly maintained to reduce potential rat problems. Good sanitary practices will not eliminate rats under all conditions, but will make the environment less suitable for them to thrive.
Rat-Proof Construction. The most successful and permanent form of rat control is to make their access to structures impossible. Ideally, all places where food is stored, processed or used should be rodent-proof. Food containers should have tight fitting lids. Seal any openings larger than 1/4 inch to exclude both rats and mice. Openings where utility conduits enter buildings should be sealed tightly with metal or concrete. Equip floor drains and sewer pipes with tight fitting grates having openings less than 1/4 inch in diameter. Doors, windows and screens should fit tightly. It may be necessary to cover edges with sheet metal to prevent gnawing.