By most standards, rats are considered pests or vermin. They can be very destructive to crops and property. Rats can quickly overpopulate when they live in a place where they have no predators, such as in certain cities, and their numbers can become hard to contain.
Rats can carry over thirty different diseases dangerous to humans, including Weil's disease, typhus, salmonella and bubonic plague. Black rats are suspected to have had a role in the Black Death, an epidemic which killed at least 75 million people in Europe, the Middle East, and Asia in the mid-late 14th century.
Because rats are nocturnal, daytime sightings of rat activity can mean that their nesting areas have been disturbed or, more likely, that there is overpopulation of them in the local area. It is typically at this point that vermin control measures tend to increase.
Rats often chew electrical cables. Around 26% of all electrical cable breaks are caused by rats, and around 18% of all phone cable breaks. Around 25% of all fires of unknown origin are estimated to be caused by rats.
Rats, particularly roof rats (Rattus rattus), can enter the attics of homes where they mate and nest. This problem occurs commonly in coastal, temperate climates and affects even the cleanest, well-kept homes. Make an appointment now to have your home inspected.
Eliminate moisture or standing water around your home.
Keep your property free of garbage and refuse, or other items that may provide food, water or shelter (such as wood piles). Store garbage in rust-resistant containers with tight-fitting lids and keep dumpster lids closed at all times.
Eliminate cracks or fissures in your home and foundation, especially near the ground. Make sure there are no gaps where pipes or wires enter your home.
Keep doors and windows closed, as brazen rats have been known to walk right in and make themselves at home.
Keep all pet food indoors.
All bird feeders should be removed if rodent activity is detected.