Evicting Animals From Buildings

Overview

Occasionally a raccoon, skunk, squirrel, or other animal will find shelter in or under a house, shed or other structure. These animals may occupy an area sporadically, using the site only two or three consecutive days or nights until available food sources are exhausted. Or, they may choose to overwinter there if the conditions are favorable. During the breeding season, females attracted to warm, dry, easily defended areas may attempt to give birth to their young in these settings.

You may choose to let the animal use the area if it doesn't pose a problem to you, your family, your pets or other animals. However, uneaten prey, urine, or feces may create odors and become a health hazard. Animals may also make considerable noise, chew on building parts, or destroy insulation during the nest-building process.

Should you choose to remove the animal, you can do it yourself or hire an animal damage control agent (Contact your local Regional Wildlife Office for animal damage control agents in your area.) An animal damage control agent is recommended for work that poses health or safety hazards. Examples include removing a large accumulation of droppings, removing a mother animal and her young, or working in a precarious location.

Note: State wildlife offices do not provide animal removal services, but they can provide the names of individuals and companies that do. To encourage an animal to move on its own or to evict it from a place where it is undesired, follow the steps below. (For information about evicting bats, also see Bats.)

A Seven Step Do-It-Yourself Strategy

Before taking any steps to resolve a wildlife/human conflict in or around a structure, you must be sure of three things:

  • What species is involved;
  • Where the animal(s) are entering;
  • Whether or not young animals are present.

Then, it is important to proceed in a humane way that also prevents the problem from reoccurring.

  1. Identify the Suspect

    You need to identify the problem species before you can resolve the problem. Note the time and location of calls, cries, or scampering noises and look outside for the animals themselves. You can often hear

    Squirrels (except flying squirrels) tend to exit around sunrise and return between late afternoon and dark, so you can identify them during daylight hours. Flying squirrels, raccoons, skunks, and opossums often make noise from dark until just before dawn; you can sometimes see well enough to identify them outside at night.

    If you can't see the animal, try to identify it from its method of entry, odor (skunk), tracks, droppings, or any damage it is causing. (Read the appropriate description in this series for specifics on any suspects.) Raccoons often leave scratches, tracks, and body oil stains where they climb up downspouts, trees, or the corners of buildings to gain access to roofs. Rats and skunks often dig under foundations or concrete slabs.

    Use a bright flashlight to locate holes in shadowy areas, and a ladder to search for holes high on a structure.

    Always be cautious around animal droppings, some of which can be harmful to people.

  2. Locate All Possible Entrances

    Inspect the outside of the structure for obvious entrances. The animal may be using more than one entry, and entry holes are often smaller than you might expect. For example, little brown bats can enter a house through an opening smaller than one square inch, while grey squirrels chew open baseball-size entries.

    The opening where utility cables and pipes enter a structure, attic louvers, roof vents, and holes in roofs, siding, soffits, and foundations (Fig. 1) are all common points of entry.

    Possible Entrances for Animals

    Figure 1: Drawing Credit - Wild Neighbors

    Use a bright flashlight to locate holes in shadowy areas, and a ladder to search for holes high on a structure.

    The house and yard offer many possibilities for shelter and cover. An overhanging branch (a) can provide access to a roof. An uncapped chimney (b) or broken vent (c) can provide access to warm, dry living quarters. Small mammals can enter where wiring or pipes enter the house (d) and (e), vents are left uncapped (f), doors are improperly fitted (g), ground-level window sills and foundations have gaps (h), and bulkhead doors (i) are not tight. Animals can also find shelter under decks (j). Burrowing animals may tunnel beneath patios (k) or wood piles (l). (Fig. 1)

  3. Locate the Animal's Main Point of Entry

    Look for a freshly dug hole, fresh animal tracks, dirt piles, nest materials, and/or hairs stuck around a narrow hole in the roof, siding, or foundation. To verify that an entry is being used, lightly stuff wadded-up newspaper, burlap, or dirt in the entry and watch daily to see if the material has been moved. Do not use this technique if you think bats or birds are entering the area because they are not capable of pushing aside the newspaper and will be trapped inside.

    As an alternative, if you suspect an opening at ground level, smooth dirt or sprinkle talcum powder outside the entry, covering an area large enough to record footprints as the animal enters or exits. Do not use flour, which may attract a hungry animal.

    If you can't find the entry, very carefully enter the attic, crawlspace, or other area during daylight hours with a strong flashlight or headlamp. Wear gloves and a dust mask and be alert for animals, their droppings, or indications of chewing. From inside, you can better inspect the screening on the vents for signs of entry. Turn off your light to reveal daylight coming through any holes in the roof or walls. Place markers in these holes so you can easily locate them from the outside when it comes time for repair.

  4. Determine Whether Young Animals Are Involved

    Proceed with the eviction process only after verifying that no young animals are present. Because each situation and each animal is different, check for young even if it seems too early or too late in the year for them to be present. Failing to do so can lead to major problems with an unhappy female that has been separated from her young.

    When you enter the attic, crawl space, or other enclosure, search for a nest or young. Focus on the area near the active entry or where you have been hearing noises. Squirrels often use insulation and other torn-up material to make nests, and site them along the outer edges of an attic. Raccoons and skunks do not make an obvious nest.

    Loudly pound on a floor joist, ceiling joist, or wall to get the young to move or make a noise that would alert you to their presence. Use a stick to search for baby animals in hard-to-reach places, such as in a wall between studs.

    Note: Use care so that you do not injure the animals. Never approach a mother with her young, as her protective instincts can make her dangerous.

  5. Evict The Family Only If It Is Necessary

    If it is necessary, try to get the mother to move the young

    If young are present, the most humane thing to do is to leave the family alone until it moves on its own. Squirrels, rodents and raccoons, however, often cause damage in attics or between walls, and it may be necessary to evict the entire family to prevent further damage to the building.

    If the young need to be moved, use one of the harassment techniques described in Step 6 to try to get the mother to move them herself. Even in an emergency, females can often be persuaded to move their young, thus avoiding the need to trap or euthanize families.

    If you are fortunate, the mother may move her young, even newborns, to an alternate den within an hour or so after they have been disturbed. If the weather is not favorable, or she has to find a new den or build a new nest, it may take a few days. Each animal is different. Some may be quite stubborn. To help the eviction process go smoothly, keep children and pets away from the animal's entry.

    Note: Whenever you try to evict a mother animal and her young, there is a chance that she may leave some or all of her young behind. If the young end up as orphans they will not survive. In this case, take the orphan(s) to a local wildlife rehabilitator or euthanize it. Do not attempt to care for the animal yourself because without the proper skills, you could further harm it. Also, it is illegal to keep wild animals without a permit. (See: Wildlife Rehabilitators.)

    If you are not successful in evicting the family and the young must be moved immediately, the female can be live-trapped and the dependent young placed in a weather-protected releasing box. Place the box outside and adjacent to the point of entry after the entry has been sealed to prevent reentry. At this point, the mother can relocate her young at her own pace. It is recommended that an Animal Damage Control agent who has experience live trapping do this work.

  6. Seal Off the Area in Stages

    The preferred option is to encourage the animal to leave and then to make sure it does not return or that a different animal does not take its place.

    1. Seal off all entries except the active one.

      Because the animal will seek other ways to get back inside, you must seal off any potential entries. Use wood, quarter-inch mesh galvanized hardware cloth, sheet metal, aluminum flashing, or another sturdy material. Plug small holes in hard-to-reach locations with wadded up wire, copper Stuf-fit, or copper or stainless steel mesh scouring pads (steel wool quickly corrodes after becoming wet). If necessary, caulk the openings to seal them; paint will help hide the repair job. With only the animal's regular entrance remaining, and during a period of fair weather, encourage the animal to leave using one or more of the following harassment methods. (Occasionally when squirrels, raccoons, opossums and other young animals leave their nest eight to 10 weeks after birth, one of the young stays behind; again, use the eviction methods described below.)

    2. Harass the animal.

      Only rarely will banging on the ceiling, wall or floor in the vicinity of the animal cause it to vacate.

      If mobile young are present, lightly pack the active entry hole with wadded-up newspaper, burlap, or dirt, and repack it whenever you see it open. Block the hole enough so the animal must expend energy to reopen it, but will not be trapped inside. When the barrier has not been removed for three days during fair weather, the animal has gone and you can make repairs to prevent reentry.

      It may be necessary to enter the area where you think the animal and/or its young may be sleeping. Be sure to wear gloves and a dust mask or respirator, and use a powerful flashlight.

      Shine the light on the adult animal, bang on a rafter, clap your hands and tell the animal to leave, or do anything that does not put you or the animals in danger. If the adult is outside, tamper with the nest by pulling off the top and/or sliding it over a foot or so.

      In addition, roll rags into tight balls secure them with twine or tape; sprinkle them with predator urine available from farm supply centers, hunting shops, or over the Internet; and throw or place them near the nest. Or, sprinkle stinky kitty litter around the nest to create an unpleasant atmosphere. Raccoon Eviction Fluid, works well with that species.

      The animal(s) may leave within the hour or it may take a couple of days. Revisit the area to see if the young are gone, and to make sure the adult did not simply move them elsewhere within the structure.

      Use wadded-up newspaper as described above to verify that the animal is gone and make the necessary repairs to prevent reentry.

    3. Intensely harass the animal.

      If the previous methods do not work, try these:

      Use a mechanic's bright drop light (a grid-enclosed bulb) or other portable light. Hang it up so it is not near burnable objects and light up the animal's sleeping area. A fluorescent light will conserve electricity and keep the heat level down. In addition, you can put a radio in the area and play a talk station as loud as you can tolerate. If the animal moves to an unlit area, transfer the light and radio or install an additional light and radio. Leave the lights and radio on continuously, day and night, to interrupt the animal's sleep.

      (There is no scientific evidence that commercially available ultrasonic devices will drive animals from buildings. Animals quickly become accustomed to the noise or move to a noise-free area; the ultrasound does not go through objects so they quickly lose their intensity with distance.)

      Use a visual verification, a one-way door (see "One-Way Doors"), or the wadded-up newspaper or talcum-powder approach to verify that the animal has gone. Be patient, as it may take several days for the animal to move, especially in urban areas where animals are used to lights and noises.

      If these methods are unsuccessful and if no young are present, you may opt at this point to live-trap the animal. (See "Cage-Trapping Wildlife").

    4. Seal the remaining entry hole while the animal is outside feeding.

      Note: Do not do this if young are present; they will be separated from their mother, which will quickly create other problems.

    5. First, assemble all of the materials that you will need to seal the entry. Next, place wadded-up newspaper in the entry or use talcum powder as described in Step 3 to determine that the animal has gone outside. For squirrels and other species that are active during the day, look for the signs that they have exited early in the morning. For raccoons and other nocturnal species, begin the surveillance an hour after dark. Survey the entry frequently, as animals will return to rest or escape bad weather. When you are certain the animal is outside, seal the entry.
  7. Follow Up

    If you hear noise coming from inside the enclosure after sealing the entry, it is likely that there is still an animal inside. Reopen the area and repeat Step 6 until all the animals have departed, then reseal the entry. If the animal will not leave the area, you can live-trap it.

    Make frequent inspections for two weeks to make sure an animal has not tried to reenter using the original opening or a new entry. Because an animal leaves a scent trail that other animals may find and follow, and this scent lasts for several months or even longer -- you may want to obliterate the scent with pepper spray or a commercial taste repellent such as Ropell. Repeat the application if the area is exposed to rain.

    Inspect for piles of droppings or other sign of activity.

    If an animal has spent a lot of time in an area with exposed wiring, inspect the area for wire damage or have an electrician inspect it. Also inspect for damage to insulation and heating ducts.

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One-Way Doors

An active entry can be fitted with a one-way door so an animal can exit but not reenter. A one-way door takes time and effort to install correctly, but is effective when you want to evict squirrels, raccoons and other above-ground animals from buildings. Commercial one-way doors that trap burrowing animals (Fig. 2) are available from companies advertising on the Internet (search for "Animal Control" or "Animal Traps").

Use a commercial one-way door to deter animals from getting under your house

Figure 2: Artist Credit - Wild Neighbors

A commercial one-way door will deter animals from burrows under houses and concrete slabs. (Fig. 2)

Use a one-way door only when you are sure that no young will be trapped inside after the adult is evicted. Thoroughly inspect the area for young prior to installing the door.

Leave the one-way door in place for seven days, or longer during particularly cool or rainy weather. To verify the one-way door's success, look for scraping or digging on the outside of the door, which means the animal is out and cannot get back in. For further proof, place a tracking patch on the outside of the one-way door, as described in Step 3, and look for prints. After all animals have been excluded, remove the door and immediately seal up the exit.

You can construct a simple one-way door from plywood, sheet metal, or quarter-inch mesh hardware cloth. Attach the top to the structure with strap hinges (wood) or fence staples (sheet metal, hardware cloth) to create a flap door that opens easily and closes completely. The door should extend beyond each side of the exit hole by at least six inches. You can weight the bottom of the door with a piece of rebar or similar heavy object to help prevent the animal from reentering. If you are using a wire-mesh door, you can also bend the free edges to create sharp points.

On angled areas (trim, eves, etc.) where gravity would keep the door open, use two small screw-eyes below the door, and run fish line from the bottom of the door through the screw eyes. Weight the ends of the line with a few metal nuts or whatever is needed to pull the door closed.

To prevent animals from digging their way back into an area where they are being evicted, one-way doors (a) are often used in conjunction with (b) an L-shaped footer made of welded wire or hardware cloth. (Fig. 3)

Use a one-way door to prevent animals from coming back to an area they were evicted from

Figure 3a: Drawing Credit - Jenifer Rees

Use a one-way door to prevent animals from coming back to an area they were evicted from

Figure 3b: Drawing Credit - Jenifer Rees

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Additional Information

Books

Wild Neighbors: The Humane Approach to Living with Wildlife
Written by: Guy Hodge
Fulcrum Group, 1997.

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