Surefire Signs of a Possible Pest Infestation

By WebFX Dev

Pest infestations bring unwelcomed insects, rodents and more into your home, business and property. You must prevent the destruction and health hazards they bring as soon as possible, but some infestations are hard to identify right away and can escalate quickly. This guide will teach you the surefire signs that will help you identify a possible pest infestation so you can counteract it quickly and effectively.

What Is a Pest Infestation?

A pest is any unwanted organism in an area populated by humans. Pests cause human concern, spread disease, cause destruction or are a general nuisance. A pest infestation is when many pests are present in an area and are causing disruption, damage or inconvenience.

Many species are considered pests, and you can identify the most common pest infestation signs in many ways. Knowing what to look for means you are one step ahead and can arrange the proper control or prevention strategies for a large-scale or problematic infestation.

What Are the Signs?

Each type of pest leaves its own specific “calling cards.” However, a few common signs of pest infestations are universal. You must familiarize yourself with these common telltale indicators that will help you identify and catch potential infestations early.


Every type of pest leaves behind droppings. The type of droppings can serve as crucial evidence that tells you what kind of infestation you may be facing.

Rodent droppings are small and oblong, much like a grain of rice. They range from dark brown to black. The most common place to find rodent droppings is near nesting areas and food sources.

Insect droppings vary depending on the insect species, from large pellets to small dark spots and smudges. You can find insect droppings in areas where they are most active, like windowsills, under beds, in dark, moist places and near food.

Bird droppings are usually white and commonly found outside, on paved areas, near windows and roofs.


Footprints are another clear indicator of a pest infestation. Rodents leave food prints in soil, dust and snow. Rats leave larger footprints than mice, but unlike squirrels, their tails drag behind them, which is also a good identifier. Squirrels move through treetops and leave fewer footprints behind. Fallen leaves or traces of bark can serve as indicators for squirrels.


Small holes, bite marks, sawdust and scratches are common signs of wood damage left by infestations. Termites and carpenter ants borrow through wood, and rodents gnaw on wood to maintain their teeth. Rodents will also gnaw on wires. Exposed, frayed and damaged cables and wiring are surefire signs of a rodent infestation.


Nesting, which is a sign of a possible insect infestation, is actually done by most types of pests — pests that have made your property their home. Rodents will gnaw holes in your house’s walls and exterior to make entrances for themselves. Rodents will build nests from gathered materials like fabric, grass or paper.

Hives, holes and mounds are the most common insect nests to look for. Products like ant traps placed near their nests can sometimes eliminate the colony.

Odors or Unusual Smells

Smells and odors are an indicator of a late-stage infestation. These smells mean enough droppings have gathered to emanate a foul aroma. Arrange for an inspection if you start to notice unpleasant, mysterious smells. This amount of droppings can be a health hazard and can trigger allergies, especially cockroach droppings.

What Are the Different Types of Pest Infestations?

There are several different types of insects, rodents and bird species that may infest your property. Let’s take a look at what these species are, why they are considered pests and the signs of a possible infestation of them.


There are four prominent signs of an ant infestation to watch for:

  • Spotting ants: An obvious sign of an ant infestation is frequently seeing ants. Seeing ants inside or outside your property can be signs of an infestation. Watch for large groups of ants or big mounds signifying a nest. Individual ants are scouts that might return to the colony to tell them where some food is.
  • Trail of ants: Seeing a trail or cluster of ants generally means they are going to a food source.
  • Sawdust: Sawdust is a sign of carpenter ants. This species bores through wood but doesn’t eat wood like termites do. They can cause a lot of damage to your home as they make their nests in your wood.
  • Rustling in the walls: Several species of ants can inhabit the walls of your building. Once one of those colonies becomes large enough, you can hear a rustling noise from your walls or ceilings.


Flies are a common pest. These are the most common signs of a fly infestation to be aware of:

  • Maggots: Maggots are the larval stage of flies and are signs of fly breeding areas. Common maggot encounters mean there is a lot of flies breeding.
  • Dark clusters: Small dark marks the size of a pinhead may appear on your wall. These indicate fly infestations, and the more you see, the more flies are leaving them behind.
  • Seeing a lot of flies: As is true with any infestation, seeing a lot of a pest is an obvious indicator that something is wrong. Regularly seeing flies and keeping them off your food all the time means you are facing an infestation. Ignoring the situation will only make things worse.


Cockroaches can damage electronics, clothes and furniture. One of the biggest issues with cockroach infestations is the health issues they bring. Here are the signs you may have cockroaches in your home:

  • Allergies: Cockroaches may trigger allergy symptoms when people are allergic to what cockroaches leave behind. Symptoms like coughing, skin rash and sinus infections are reactions people can have to cockroach infestations. Allergens come from cockroach droppings and their skeletons in particular.
  • Droppings: Cockroach droppings are dry that resemble coffee grounds or clusters of dark specks. They are minute and easy to miss. Look for them in dark areas like closets. Areas with a lot of droppings show that cockroaches are common around that spot.
  • Egg casings: Cockroaches breed quickly due to their short lifespans. Cockroach egg casings are a surefire sign of an infestation and breeding areas. You are likely to find these egg casings under furniture like beds and couches. They are oval-shaped and brown in color.
  • Shed skin: These insects have no internal skeleton. Their hard outer casing is what keeps their organs inside them. Cockroaches shed their exoskeletons as they grow. You’ll find evidence of their shed skin in moist, dark places.
  • Seeing roaches regularly: Smokey browns are a species of cockroach that only breed indoors. You are being invaded when you see lots of smaller cockroaches, like German cockroaches or similar.


There are approximately 50,000 known spider species in the world, it’s common for spider infestations to occur. You know you have a spider infestation when you see these signs:

  • Webs: It is well known that spiders make webs. Different species make webs in different places and ways. Some are easy to spot, while some make them in trees and bushes. Constantly Clearing webs suggests more than one arachnid living in your home.
  • Spider egg sacs: If you spot a silk ball in your home or garden, a spider’s nest has hatched. Spiders lay hundreds of eggs at a time and store them in these special egg sacs. In general, spiders mate in Autumn and cool nights in late summer, so stay diligent during these times.
  • Bites: Small bites on your body may signify a spider infestation, but many other insects also bite humans. You can identify a spider bite by the two puncture wounds they leave. Different spider venom can have varying effects, from fatigue to headaches. If you frequently find mysterious bites on you, it may mean you have a spider or insect infestation.
  • Lots of bugs and insects: Every house has bugs, especially outdoors. However, an unusual amount of bugs inside or outside might lead to a spider infestation. Spiders feed on insects, so if there are a lot of them to feed on, it is likely that spiders will stay, thrive and breed in your home.

Wasps and Hornets

Wasps and hornets may be entirely different species, but they leave a lot of similar signs of infestation. You may have a hornet or wasp infestation if you experience the following:

  • Nests: Wasp and hornet nests are structures made out of honeycomb-shaped holes. If you see one on your property, a colony has invaded. They will protect their home, so disposing of them is best left to a professional.
  • Buzzing noises: Both hornets and wasps make a loud buzzing sound. Many of them together can make a very noticeable noise. Listen out for loud, constant humming to identify where their nest is.
  • Damaged wood: Paper wasps or hornets make their homes from chewed wood and saliva. Small holes in fences, firewood, trees and wooden objects in your home suggest the presence of a paper wasp or hornet’s nest.

Rats, Mice and Squirrels

Rats and mice are separate species, but they have a lot of behaviors in common. As such, they can be identifiable in very similar ways. Here are some specific signs to look out for:

  • Droppings: Mice, squirrels and rat droppings are dark and moist but become gray and dried up when left for a while. Droppings are a definite sign that mice and rats are nearby and active.
  • Smells: Outside of their droppings, there are other smells to keep a nose out for. Rodent urine smells like ammonia and can be quite pungent. You will only pickup this smell when there are a lot of them around. Another foul odor can come from dead mice and rats. This strong smell can linger for a few days.
  • Holes and bite marks: The most common type of damage mice and rats leave behind is bite marks. They gnaw constantly, and walls, furniture and wires are prevalent targets for them
  • Rodent nests: Rats and mice make their nests out of organic and inorganic materials they find around your property. They gather common building materials for paper, grass, plastic, packaging and cloth.
  • Scampering and scratching sounds: Rats, mice and squirrels are noisy occupants, especially at night. Scampering and scratching noises in your walls and ceilings clearly indicate a rodent infestation. You can tell where they are and determine their most active times by listening out for them,
  • Pet behavior: Cats and dogs can act differently during a rodent infestation. If your dogs are barking more, seem interested in specific areas of your house or act more territorial, this might suggest they smell a group of intruders.
  • Rodent runways: Rodents use the same path when they enter and leave their nests. Footprints, grooves in your grass patches or soil and droppings are often indicators of a rodent runway.
  • Squirrel-specific signs: Some additional signs suggest a squirrel infestation. Squirrels will mostly stay in attics, ceilings or chimneys. They are more likely to cause damage to your roof, air vents, bird feeders and outdoor furniture, make holes in shingles and scatter wood chips and food scraps.


Moles are destructive garden pests that can cause quite a lot of damage. The signs of a mole infestation are:

  • Molehills: Raised ridges, sand mounds and molehills are the most noticeable signs of a mole infestation.
  • Discolored grass: Moles damage grass roots as they tunnel through your garden. Dead or discolored grass is a clear sign of moles in your yard.
  • Loose soil: Moles leave behind loose soil as they dig. This can weaken some garden patches, resulting in uneven ground.
  • Weeds: Moles damage or destroy plant roots while they dig. This kills the plants and lets weeds take their place and flourish.


Pigeons are common birds in almost every urban and suburban area worldwide. Sometimes they can make your home their nesting grounds, which can be inconvenient. This pest may not be as destructive as others but is still best to avoid. Look out for these signs of a pigeon infestation:

  • Cooing noises: Pigeons are noisy birds, especially en masse. Their chicks are also very noisy as they constantly call their parents for food. Pigeon cooing, wing flapping and dull thuds when they land on your roof are the most common sounds they make.
  • Droppings: Bird droppings accumulate quickly below their nesting and roosting areas. This is an easy sign to spot. They mostly live in easily accessible places protected from rain and wind.

Call Pestech at the First Sign of an Infestation

Pestech knows how to spot an infestation and knows how to control it. We’re a family-owned pest control business that has been working with businesses, restaurants, hotels and homes since 1989. We provide home and business inspections and can provide you with the best pest control strategies. Contact us today to learn more about what we can do for you.