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What Does A Rat Infestation Look Like?

By July 8, 2023No Comments

A rat infestation is the last thing you want to happen in your house. Rats are destructive and they carry deadly diseases. You don’t want to compromise your family’s health and you also don’t want to spend hundreds of dollars exterminating them.

But how can you tell if there’s a rat infestation or not? What are the signs of a rat infestation and what’s the immediate thing that you need to do to get rid of it?


Rats are interesting but horrifying creatures. They can easily multiply, and they love to hide in the dark. There are other things that you need to know about these nasty household pests. Here are some of the horrifying facts about rats that you need to know.

  • Rats can swim through pipes and your toilet. That’s true, rats can swim through any pipes where they can fit in and through your toilet. This means that the house pipes, sewage system, and drainages can be a common rat thoroughfare. They’re really good swimmers and they can squeeze themselves through narrow tunnels.

  • Rats can produce up to 6,000 babies in their entire lifetime. The reason why rat control is critical is because of their ability to multiply fast. They’re extremely prolific. Rats can breed as early as three months of age and they can breed like rabbits.

  • They can grow their teeth up to 15 centimetres on average in a year. Rats use their constantly growing teeth to gnaw on bricks, cement, wood, food, and even animal bones. Now, imagine seeing a rat who’s not used its teeth for gnawing for over a year. That’s going to be a nasty sight.

  • Rats can be invisible. Rats can’t be literally invisible, but they can be very adept in blending in and camouflaging with their environment. More importantly, they’re extremely hard to catch. In some countries, it takes more than five months just to capture a single rat. That’s how clever and smart they are in terms of obscuring themselves to humans.

  • What rats really want is your flesh and blood. This might sound more like a horror movie plot but it’s true. Rats treat humans much like everything else they see: FOOD.


According to the Center for Disease Control and Prevention (CDC), rats and their relatives carry 7 known diseases that can be fatal for humans.

  • Hantavirus pulmonary syndrome or HPS
  • Leptospirosis
  • Lymphocytic Choriomeningitis (LCM)
  • Bubonic Plague
  • Salmonellosis
  • Tularemia or rabbit fever
  • Rat-Bite Fever

These diseases can be transmitted through breathing, touching, and bites. Another common method of transmission is through open wounds where the pathogen can enter through the body. That’s why it’s extremely important to exterminate rats and performing thorough cleaning and disinfection after a rat infestation.


Rats are nocturnal creatures that are smart enough to evade human visibility. They hide in the dark and warm corners of the house. They’re patient enough to wait until everybody in your household is comfortably resting before they go out and have fun.
Rats are really hard to detect until you start seeing one crawling on the surface or lying around dead in one corner. The telltale signs of a rat infestation can be observed through the following:

  • Rat nests. A very good sign of a rat infestation is the existence of rat nests. If you don’t know what this looks like, rat nests are simple nests made of any materials inside your homes, such as papers, fabric, loose clutter, or even insulation. Rats drag these materials into an isolated area in your house, usually under furniture or any dark corners in the house. Rats can also build their nests inside walls. Rats are known to break down these big materials into smaller pieces and make them into materials for their nests. They crumple paper, rip chunks of insulation, tear strips of fabric, or break pieces of wood into smaller pieces. These nests are unorganized and can even be confused simply as garbage.

  • Gnaw and scratch marks. Rats never stop gnawing because their teeth don’t stop growing. In order to keep their teeth healthy and sharp, they have to continue to gnaw. Rats will gnaw almost everything they can see. When you start seeing tiny damages, gnaw marks, or scratches on walls, furniture, plastic, cardboard, insulation, and/or paper products, then you’re pretty certain that a rat is responsible for them. These gnaw marks or scratches can be very subtle and hard to notice right away. Damages on surfaces or walls caused by rat bites are usually just about 2 inches or smaller in diameter. Gnaw marks are a lot more subtle. However, rat damages to electrical wiring, cardboard, and other soft materials can be very obvious. Damage done by rats on electric wiring insulation be very dangerous as it compromises the integrity of the insulation and the wiring. This can cause electrical and hazards at home.

  • Grease and rub marks. Rats have poor eyesight, but they do have heightened smell and hearing. Rats are also known to use the same routs every day. Because of this, rats leave marks on the surfaces they pass by every day, such as oil, grease, dandruff, and/or dirt. Rats can stain the walls where their fur can press upon. When you start noticing these marks, you have to be ready for full-blown rat extermination. Rats are also known to leave footprints or running tracks with their feet and tail. You’ll discover this when you sprinkle talc or flour along a small stretch of floor or surface.

  • Rat droppings and urine. Rat droppings are one of the surest signs of a rat infestation. Rats drop small pellets that are typically around 0.3 centimeters wide and roughly 1-centimeter long. These dark brown or black droppings are soft and moist. These are usually dropped on nearby surfaces, corners, nests, cupboards, furniture, and/or pantry. These droppings will dry over time and become gray and brittle. When they break, they might get crushed into smaller pieces and can mix with dirt. These can become a lot more dangerous since rat droppings contain a lot of pathogens that can cause diseases to humans. Another common sighting is rat urine stain. While rat urines don’t necessarily flood, the stain that they leave behind is fairly obvious. In addition, the urine leaves a pungent smell. These stains can be found on surfaces, carpets, and/or fabrics.

  • Foul and pungent odor. A clear sign of an active rat infestation is the presence of a foul and pungent odor. Typically, dogs and cats become excited when they catch this smell. You’ll notice your pets become unusually active where they try to paw over an area they’re not previously interested, it’s certain that there may be a rat hiding. Recurring stale smell that can linger around the house can be a sure sign of an active rat infestation.

  • Burrows. Rats, especially brown rats, are typically known for excavating and digging widespread burrow systems. They use these burrows for nesting, food storage, and shelter. If you want to investigate a rat infestation, you can start by looking for burrows under garden sheds, compost heaps, and garages.

  • Scratching and/or teething noises. The tiny, screechy noises you hear at night are not at all cricket sounds. Black rats are known to climb roofs and they pass through loft spaces and ceilings. Brown rats on the other hand are known to scurry under floorboards, decking, and sheds. The scratching noises you hear usually come from these rats scratching walls, surfaces, or materials they use for their nests. Brown rats are also known to produce grinding noises as a result of bruxing.


Hire a professional pest management expert to get rid of a rat infestation right away. Don’t compromise your family’s health let alone the damages that rats are doing to your home. GTA Toronto Pest Control offers excellent rat and rodent removal that exceeds your satisfaction.