What causes a rat infestation?
Rats, like all rodents, are opportunistic creatures looking for food, water and shelter. If they can find these three things easily available, they will take up residence in a home or building and begin to breed rapidly. Some common causes of rat infestations include:
- Access to food sources – Pet food left out, unsealed garbage cans, compost piles, fruit trees, chicken coops, vegetable gardens and pet bowls can all attract rats looking for an easy meal.
- Access to water – Leaky pipes, pet water bowls, birdbaths, clogged gutters or rain barrels can provide a water source.
- Clutter and debris – Rats love to nest in woodpiles, junk piles, overgrown vegetation, abandoned sheds and other cluttered areas that provide shelter.
- Cracks and holes – Any openings larger than a quarter inch can provide entry points into a home for rats. Cracks in foundations, gaps around pipes, holes gnawed by other rodents, and loose vents or screens can all allow access.
- Nearby food businesses – Homes and buildings located near restaurants, grocery stores, farms, landfills or other food businesses may deal with migrating rat populations drawn by the smell of food.
Identifying and eliminating these attraction factors is key to preventing and eliminating rat infestations. Rat populations can grow rapidly once established, with females breeding every 2-3 months and producing 5-12 babies per litter. So early prevention is critical.
Signs of a rat infestation
Here are some common signs that may indicate the presence of rats in or around a home:
- Droppings – Finding small, oblong black droppings is one of the most obvious clues. Rats produce 50-75 droppings per day.
- Gnaw marks – Rats gnaw constantly to wear down their teeth. Look for gnaw marks on wood, pipes, plastic, drywall and other materials.
- Nests – Rat nests may include shredded paper, fabric, cardboard and other clutter.
- Rub marks – Rats leave greasy rub marks along their frequently travelled paths such as along walls and beams.
- Noises – Rats are active at night and may make scurrying, scratching or squeaking noises in walls, attics, crawlspaces or ceilings.
- Musky smell – A strong musky odor from rat urine and secretions may be noticeable, especially in enclosed areas.
Catching sight of live rats around the home is also an obvious indicator. Spotting just one adult rat likely means a larger infestation is already established nearby.
Potential risks from a rat infestation
Beyond just being a nuisance, rat infestations also pose some health and safety risks:
- Disease transmission – Rats can spread over 35 diseases to humans through their urine, droppings and bites. These include salmonella, E. coli, rat-bite fever, and Leptospirosis.
- Contamination and damage – Rat urine and droppings contain bacteria and pathogens that can contaminate surfaces, food, and belongings. Rats also cause structural damage by gnawing and nest-building activities.
- Asthma triggers – The dust, dander and detritus from rat nests and bodies can trigger asthma symptoms.
- Fire hazard – Rats are known to chew on electrical wires, increasing the risk of electrical fires in walls and ceilings.
- Aggressive behavior – Cornered rats may bite or attack pets or small children. Rats carry and transmit rabies too.
So allowing rats free reign puts a home’s occupants at risk. Consulting a professional exterminator at the first signs of infestation is recommended. DIY control methods may simply scatter the infestation or fail to fully eliminate it.
Methods for getting rid of a rat problem
Here are some common methods professionals use to control and eliminate rat infestations:
Inspection and exclusion
The first steps are inspecting the home to find all possible entry points, and sealing up any openings with weather-resistant sealant, steel wool, copper mesh, cement, hardware cloth or other exclusion materials. Rats can squeeze through very small gaps.
Sanitation and habitat modification
This involves clearing clutter and debris from around the home, moving woodpiles far away from house foundations, cleaning up vegetation and food material, using tightly sealed metal trash cans, and securing any food sources. Removing their habitat and food makes the area far less attractive to rats.
Trapping
Trapping is an effective method of removing rats. Snap traps or live traps are set out along rat travel paths, baited with peanut butter, fruit, bacon or other rat favorites. Traps must be checked daily and dead rats disposed of properly.
| Trap Type | Pros | Cons |
|---|---|---|
| Snap traps | Inexpensive, traps and kills rats | Can bedangerous around children/pets, must dispose of dead rats |
| Live traps | Catch rats alive for release elsewhere, more humane | Must check frequently, release rats far away to prevent return |
Poison baits
Rodenticide baits containing chemicals such as warfarin, brodifacoum or diphacinone are deployed in bait stations. Rats are attracted to the bait and die after consuming it. Caution must be used with poisons, as dead rats can be hard to find leading to odor issues, and poisoned rats can be hazardous to pets or wildlife that consume them.
Fumigation
In severe infestations, fumigation of the full home with sulfuryl fluoride gas may be required. Residents must fully vacate the home for several days during the process. This method kills all rats inside at once but does not prevent future infestations unless exclusion and habitat modification is also performed.
Preventing future infestations
After eliminating a rat problem, there are some key prevention measures to avoid re-infestation:
- Seal any cracks and holes with steel wool, caulk or other materials, especially around the foundation. Install weatherstripping around doors and windows.
- Keep vegetation trimmed back from the home exterior to eliminate hiding spots.
- Clean up clutter in and around the home such as woodpiles, junk debris, stacked materials, etc. Move compost bins far from home foundations.
- Store food properly in sealed metal or glass containers. Keep pet food put away and empty garbage frequently.
- Install light fixtures around sheds and exterior areas to deter rats from foraging in darkness.
- Consider a cat – rodents tend to avoid homes and areas patrolled by feline predators.
With diligent exclusion and habitat modification, the risk of repeat infestations can be substantially decreased. But it’s smart to continue monitoring for signs of rat activity and address problems immediately before they spiral out of control. Early intervention is key for effective and affordable rat control.
Conclusion
Rat infestations should never be ignored. A proactive integrated pest management approach combining exclusion, sanitation, trapping and population control is required to get rid of rats and keep them away for good. The risks to health, home infrastructure, sanitation and quality of living are simply too great. By understanding rat habits, behavior and biology, and denying them food, water and access into structures, rat problems can be resolved and prevented in the future. But professional expertise is usually required to fully eliminate large infestations. With persistence and dedication to exclusion principles, even the most severe rat invasion can be sent packing for good.