To view graphic version of this page, refresh this page (F5)

Skip to page body

Living with Local Wildlife

A common misconception is that setting a live trap, catching the raccoon, skunk or opossum and destroying it or relocating it will take care of the nuisance. However, before too long another raccoon, skunk or opossum will move into the area. If it was a good habitat for one, it's just as good for another. Urban wildlife enjoy the easy life we often unknowingly provide for them; they don't like a hostile environment. Taking steps to deter them will encourage them to move on.

Living with Raccoons

Raccoons rarely exhibit a fear of people or civilization, since they are born and raised in our neighborhoods. They have replaced their former nesting places with attics, crawlspaces, hot tubs, decks, tool sheds and storm drains. Dog and cat water bowls, swimming pools and ponds have replaced water sources such as creeks and springs. Raccoons are nocturnal animals who roam their neighborhoods each night looking for food. They are opportunistic feeders, dining on insects, fruits, vegetables, acorns, seeds, fish and small mammals, as well as dog and cat food and garbage that is left out overnight.

The only long-term, permanent means of coping with troublesome raccoons is to exclude them from areas you do not want them. If they cannot get a meal at one place they will look elsewhere, and they will remember where they can and cannot expect to have their hunger satisfied.

  • Motion-sensitive lighting kits and motion-sensitive oscillating sprinklers can also effectively deter nocturnal raids on trashcans or gardens.
  • Repellents: Ro-Pel® contains both a bittering agent and a penetrating agent to allow it to better absorb into plant tissue or other material. It works by imparting an extremely bitter taste to anything it contacts. Get-Away® uses extracts of oil of mustard and capsaicin as both an odor and taste repellent.
  • Regular household ammonia stations can be placed around your yard in the areas frequented by raccoons. Take a shallow dish or bowl, place a rag in it and pour ammonia over the rag until completely saturated. Place enough ammonia in the dish so the rag will continue to wick the ammonia up through the night. Avoid lawn areas, as ammonia will burn grass.
  • Use a metal trashcan and secure the top with a thick rubber strap with hooks on the end, available at most hardware stores. You can also secure the can to a fence.
  • Place piles of cayenne pepper or a repellent where raccoons are digging in your recently sodded lawn for worms and grubs may discourage them.
  • Situations with raccoons in chimneys and attics involve raccoon families; a flue makes a cozy den for giving birth. When a mother raccoon with young is present, we recommend leaving them alone for the few weeks that the young are helpless. Monitor the raccoons to determine when they have moved on their own accord, then secure the entrance to the chimney or attic to prevent re-entry. Trapping and moving the family will almost always lead to separation and probable death of the young.
  • Important! If you have a female with babies, give her extra time to relocate her entire family before you close the entrance. Raccoons have several den sites within their territories, so she will need to check for a vacancy, then move the young one by one, taking possibly two or three days. Do not lock the mother out, since she will return to retrieve her young and may damage your house to reach them. There is also the possibility that the young may die, leaving you with a smelly mess.
  • Capping your chimney will prevent a raccoon from inhabiting it. Because raccoons are nocturnal, the best time to use repellents or frightening strategies to get them out of a chimney is right before the animal would normally start his nightly routine.
  • Check your property regularly to make sure that screens barring entrance into your home, basement or crawlspace is intact.
  • Lock dog and cat doors at night and place ammonia stations in front of the locked door.
  • If a raccoon should establish himself under your house, place a radio near his nesting place and keep it on loud during the day. Locate all entrances and exits. Block them off except for one and use repellents or frightening strategies to encourage the raccoon to leave. To be certain the animal has departed, sprinkle flour at the exit and watch for footprints that lead away from the opening. When the raccoon leaves to begin his nightly hunting (usually two hours after sunset) block the remaining entrance.
  • Ponds should be three feet deep. Horizontally submerging wire mesh around the circumference of the pond can provide the fish with protection since the raccoons will most likely stay off the flimsy wire. Placing a single "hot" electric wire around the perimeter of the pond from four to eight inches off the ground will not only discourage raccoons, but neighborhood cats. It can be made removable so family members can enjoy the pond during the day.

Living with Skunks

Skunks are found in every neighborhood in San Francisco. Skunks rarely exhibit a fear of people since they are literally born and raised in our backyards. They are chiefly nocturnal animals. While their diet primarily consists of rodents and insects, it may also include carrion, eggs and garbage. If approached by an intruder and unable to flee, they may stamp their forepaws and scratch the ground in warning. If pursued after this point, the skunk may spray. If you see a skunk displaying this behavior, back away quietly and slowly.

 

  • The most effective method of discouraging visits by a skunk is to secure metal trash containers with tight-fitting lids and to hold the lid in place with a thick rubber strap.
  • Remove attractants - garbage, dog or cat food left out at night, open compost piles, a pond, fruit trees and vegetable gardens -- from the vicinity of your house.
  • Elevated sheds, openings under concrete slabs and porches, and access to crawl spaces under houses are all attractive to skunks and other wildlife because they make ideal denning sites.
  • Motion-sensitive oscillating sprinklers have been very successful in deterring skunks.
  • Ro-Pel® and Get-Away® are taste and smell repellents available for use in target areas. You can also place regular household ammonia stations around your yard in the areas frequented by skunks. To do this, take a shallow dish or bowl, place a rag in it and pour ammonia over the rag until it's completely saturated. Place extra ammonia in the dish so the rag will continue to wick it up through the night. Avoid lawn areas, as ammonia will burn the grass.
  • When a mother skunk and her young are present, we recommend leaving them alone for the few weeks that the young are helpless. Monitor the skunks' activities to determine when they have left for good, and then secure all entrances to the nest site to prevent re-entry. Trapping skunks is rarely necessary and should never be done while they are nesting.
  • Important! If you have a mother with babies, be sure to give her extra time to relocate her entire family before you seal the entrance to their den. If the parent is gone but you are unsure whether the young are also out, do not seal the opening. The babies will starve and possibly discharge their spray before dying if trapped in the den. (Consider using a mild deterrent such as a radio to accelerate the skunks' departure from the den.)
  • Make sure that all air vents and openings to crawl spaces and other potentially accessible areas are secured. Skunks are rodent predators who often follow mice and rats into these areas. Close openings around decks, stairs, sheds and hot tubs.
  • Keep woodpiles elevated off the ground and pick up any debris that could potentially house a skunk den.
  • Place a radio near a known skunk den and keep it on loud during the day. Wait until the animal has begun their nightly foray and locate all entrances and exits. Block all except one and use repellents or frightening strategies to scare the skunks out. To be certain the animals have left, sprinkle flour at the exit and watch for footprints that lead away from the opening. When you are sure the animal is gone, securely close the opening.
  • Because they normally do not climb, fencing is a highly effective means of keeping skunks out of your yard. By attaching an extension of chicken wire along the base of your fence and buried beneath the ground's surface, you will prevent skunks from gaining access by digging under the fence.
  • Vegetable gardens can attract skunks, although they are mainly interested in the harmful rodents and insects that can ruin your garden. While foraging for grubs, skunks may dig many shallow holes in the lawn; similar to those made by both raccoons and squirrels. A nursery or garden center can advise about how to prevent grubs.
  • The best way to protect your dog, cat or other companion animal from wildlife is to keep them inside at night. Domestic animals left in the yard where a skunk might live or forage could be sprayed anytime from dusk to dawn. Dogs generally are sprayed because they chase or threaten skunks. If you need to let your dog out during the night, turn on the patio lights first and scan the yard visually before letting releasing him. If your companion animal is sprayed, we recommend commercial deodorizing products available at your local animal supply store. Skunk spray will dissipate over time.

Living with Opossums

The opossum is approximately the size of a house cat, with grayish-white fur that can vary from almost white to almost black. Feet and legs are black; toes are white; ears are naked flaps of skin. Tracks will show an opposable thumb on the rear feet. The long, naked, scaly tail is prehensile and is often used as a fifth limb. Opossums weigh between four and eight pounds, are two to three feet long, and can live from two to six years.

 

Opossums are found in all types of habitats, but they usually prefer deciduous woodlands. They favor dens on the ground, which can lead them to take up residence under decks and in crawlspaces. While female opossums spend their lives in more defined areas, the male opossum may wander continuously. Over the years we have changed their habitats into our living spaces and they have had no problem adapting to our lifestyles. Opossums no longer exhibit a fear of people or civilization, since they are born and raised in our neighborhoods.

Opossums are slow-moving, omnivorous animals who roam properties at night looking for food. Carrion forms much of the opossum's diet and is supplemented with fruits and vegetables, (persimmons, apples and corn are particular favorites), insects, frogs, eggs, birds, snakes, mammals and earthworms, as well as dog or cat food or garbage left out at night.

When confronted, opossums often bare their teeth and hiss. While they may look fierce, they generally are nonaggressive and shy. Rather than fight, when hard pressed they will sometimes slip into the death-feigning catatonia that we term "playing possum." The animal's system reacts automatically, throwing the brain and nervous system into a catatonic state that lowers their heartbeat and respiration.

The first and best approach to dealing with wildlife in urban environments is to practice tolerance -- understanding and acceptance of the natural patterns of animal life and respect and appreciation for wild animals. As useful as the repellents and scare devices described below may be, they all create inconvenience and displacement or even death for the opossums and perhaps other species as well.

The only long-term, permanent means of coping with troublesome opossums is to exclude them from areas where you do not want them. Opossums are wanderers, and if you see one in your yard, he is probably just passing through.
Since opossums are omnivorous and are one of nature's best scavengers, make sure to not inadvertently provide them with a food source.

  • In general, they do not have behaviors that cause property damage. Because they are not diggers, they are rarely the culprits if the soil or sod has been turned over.
  • Hand-sized motion detectors (usually combined with bright lights) and alarms, intended for indoor use, can be used in crawlspaces or, with proper protection from the weather, in some outdoor situations.
  • Motion-sensitive lighting kits are also effective in situations for nocturnal raids on trashcans or gardens. Motion-sensitive oscillating sprinklers are also available for deterring nighttime visitors.
  • Repellents: Ro-Pel® contains both a bittering agent and a penetrating agent to allow it to better absorb into plant tissue or other material. It works by imparting an extremely bitter taste to anything it contacts. Get-Away® uses extracts of oil of mustard and capsaicin as both an odor and taste repellent to repel wild animals. You can place regular household ammonia stations around your yard in the areas frequented by opossums. Take a shallow dish or bowl, place a rag in it and pour ammonia over the rag until completely saturated. Place enough ammonia in the dish so the rag will continue to wick the ammonia up through the night. Avoid lawn areas, as ammonia will burn the grass.
  • Make sure that screens barring entrance to your home, basement or crawlspace is intact.
  • When an opossum is known to be denning under a porch or patio, place a radio near where the opossum is nesting and keep it on loud during the day. When the animal leaves for her nightly foray (two hours after dark is generally a safe time), locate all entrances and exits, blocking all except one. Loosely close this last opening with netting, straw or another fibrous material than an animal trapped inside can push away, but one on the outside will be less likely to disturb to get back in. To be certain the animal has left, sprinkle flour at the exit and watch for footprints that lead away from the opening. When you are sure the opossum is gone, securely close the opening.
  • Lock dog and cat doors at night and place ammonia stations in front of the locked door.
  • Secure trash containers with tight-fitting lids and a thick rubber strap, and to bring in your companion animal's food and water dishes each evening. (Replace food and water bowls with ammonia stations during nighttime hours.) If you encounter an opossum in your garbage can, simply tip the can on its side and allow the animal to leave on his own.
  • Securely close the areas around decks, hot tubs and sheds. Opossums are rodent predators and will often follow mice and rats into these areas.

Living with Tree Squirrels

Squirrels often depend on trees for places to bear and raise young, take shelter from the weather, find food and escape from predators. They use tree cavities and leaf nests as dens. When it's available, squirrels will also take liberal advantage of shelter provided by humans in attics and crawlspaces along the upper floor of buildings. Squirrels are only active during the day. When you observe damage, first make sure it is not being caused by another animal.
Squirrels feed mainly on plant material, which vary with geography and season. Acorns and other nuts are both eaten and stored underground in the fall and early winter, with the underground storage making up a substantial portion of the winter diet. In the spring and summer squirrels eat the flowers and growing buds on the terminal ends of branches and a variety of fruits.

 

Prevention is the key to dealing with squirrels. Because tree squirrels are extremely agile, they can access just about every square inch of your property and your home. The most serious squirrel-related problems usually develop when adult females enter a building to establish nests. In their search for a den site, they will explore all potential openings, and often enter chimneys or attics through unscreened vents or openings left by loose or rotting boards. Squirrels enter buildings somewhere high on the structure and will exploit an existing hole, sometimes enlarging it by gnawing. Your first sign of a squirrel's presence is usually the sound of scampering in the attic or above the fireplace.

It is important to remember that these animals are only doing what is natural for them -- seeking a warm, dry place to stay, raising their young and search for food at a time of the year when shortages are critical and death is imminent. The first approach to dealing with squirrels is to establish limits of tolerance, accept them for what they are and be patient. If you must exclude them from an attic or prevent them from stealing bird food, do so in a way that does them and their young no harm.

You can use hand-sized, indoor-use motion detectors (usually combined with bright lights) and alarms to keep squirrels from entering attics and crawlspaces. With proper protection from the weather these are also options in some outdoor situations.

Repellents: Several commercial repellents are registered for use with squirrels. Some, such as products that contain Thiram, can be used to soak bulbs before planting. Others are intended to be sprayed on ornamental plants that squirrels are attacking. Ro-Pel® contains both a bittering agent and a penetrating agent to allow it to better absorb into plant tissue or other material. It works by imparting an extremely bitter taste to anything it contacts. Get-Away® uses extracts of oil of mustard and capsaicin as both an odor and taste repellent to discourage squirrels.

If a squirrel is trapped in your chimney, hang a ¾-inch or thicker rope down the chimney to provide a means of escape. Be sure to tie one end of the rope to the top of the chimney before lowering the other end, and make certain that it reaches the damper or smoke shelf. The squirrel will climb up the rope and escape, usually within a few (daylight) hours. After you are certain the squirrel has escaped, remove the rope and screen the chimney, preferably with a commercially made chimney cap. Do not try to smoke a squirrel out of a chimney; a trapped squirrel and her babies may be killed and would be difficult to remove.

If a squirrel is down in the fireplace (presumably behind the fireplace doors or screen), try tapping on the door and scaring them back up above the damper. If successful, close the damper and proceed as above. If the squirrel cannot or will not leave the fireplace, your next best option is to close any interior doors in the room and open an exterior door or window visible from the fireplace. Open the door to the fireplace and sit quietly. The squirrel will instinctively head for the light of the open door or window and go outside.

If you have an adult squirrel in your attic, attempt to frighten them outside by banging on the rafter inside the attic, or wait until you are sure all squirrels have left, as they usually do during the day. Then seal up the opening with ¼- to ½-inch mesh hardware cloth or sheet metal flashing, securely fastened. Extend the metal patch at least six inches beyond the hole in all directions to prevent the squirrel from gnawing around the patch. Seal any other weak spots or potential entrances in the same way. Watch closely to see if the squirrel persists in attempting to regain entry. Mothers will go to extreme lengths to reunite with their young and can cause extensive damage to houses when doing so. Usually when a mother squirrel feels threatened she will relocate her brood. Be sure to allow her extra time to move her babies before sealing openings permanently.

Protect fruit trees that are isolated from other trees by wrapping a two-foot band of sheet metal around the trunk about six feet off the ground. Branches growing below six feet may have to be trimmed. Covering planters with chicken wire allows plants to grow through, but blocks access to soil where squirrels can dig. Enclosing entire gardens with mesh wire may exclude other animals as well.

Thank you to our friends at The Peninsula Humane Society / SPCA for providing this information. If you would like to speak with a Wildlife Consultant, please call Animal Care & Control at (415) 554-6364 for a referral.

 

1200 15th Street
(at Harrison St.)
San Francisco, CA 94103
415-554-6364
acc@sfgov.org
Cats106

 

Last updated: 1/16/2014 3:08:55 PM