Inspection Unit 4A

Prevention and Species

Prevention Part 1

This section covers how to help your clients prevent future animal damage. Whether the customer has suffered animal damage or not, ethical inspectors educate clients about how to reduce the property’s attractiveness to home-seeking animals.

This section also provides brief field notes for what to look for when inspecting for animal damage caused by the most common property-damaging species.

Any inspector would be remiss if he didn’t suggest ways for a client to prevent future animal damage problems. Here are some tips on preventing problems that you can recommend to your clients. 

There are 3 basic strategies to prevent conflicts with animals, namely

  • food reduction,
  • habitat modification, and
  • exclusion.

Of the three strategies, food reduction and exclusion are the most important and, fortunately, the least expensive strategies to implement. Any effective long-term plan to reduce human-wildlife conflicts must begin with food reduction. People are always shocked when I inform them that birdfeeders are my best friend. Bird feeders are essentially a free grocery store for a variety of animals such as mice, voles, chipmunks, squirrels, raccoons, and opossums. What customers don’t realize is that in many animals, the fertility of the female is governed by how much food she has available. For example, gray squirrels have anywhere from three to five young during each pregnancy. However, if she is well fed, then the chances are great that she will give birth to five young rather than three. Considering that gray squirrels mate twice a year, you have a recipe for explosive squirrel population growth. Since there aren’t more den trees for the squirrels to dwell in, they just live in what is available, namely your house. Remember that nature follows supply-side economics. If there is a supply, then there will be a demand to meet it. If there is an ample supply of food, then more animals will come to consume it.

For those of you who enjoy watching birds during the winter months, here are a few suggestions. First, make sure that squirrels cannot reach your bird feeder under any circumstances. I am sure that you have heard that it is impossible to prevent squirrels from getting to your bird feeder, but this just isn’t true. Positioning your feeder on a pole (at least ten feet away from nearby branches) with a squirrel baffle should do the trick.

Second, minimize the amount of seed that can reach the ground. Squirrels, mice, voles, etc. can and will forage any seed that has fallen on the ground. Simply placing a flat board or plate underneath the feeder to catch food will do the trick. However, you must routinely clean off the board/ plate regularly. If you would like to feed ground-feeding birds like mourning doves, then spread the food on a smooth surface like a blanket or driveway and remove the remaining food after they have fed. Do not leave the food out overnight or if you notice squirrels eating along with the birds.

Trash cans are another major food source for raccoons, skunks, and opossums. It seems that no matter how tight the bungy cord is fastened, a raccoon can still lift the lid. The solution is simply to leave the cans inside the garage or a storage shed.

Rubbermaid trash can protector. Rubbermaid makes a trash can holder that can be effective in securing trash from prying animals in search of an easy meal (Photo by Stephen Vantassel). If neither a shed nor a garage are available, you can build a wood box with a lid to hold the trash cans inside. It can be made out of plywood and screws in a relatively short amount of time. Preventing animals from raiding the cans placed at the curb for trash collection is a simple matter. First, minimize the amount of garbage placed in your trash by utilizing your sink’s garbage disposal. Next, spray the trash with bleach and/or baby powder to mask the food odors.

Habitat modification is the most expensive strategy to reduce animal/human conflicts. It essentially consists of removing or changing the living environment that the nuisance animal finds attractive. For example, if chipmunks are driving you crazy, then removing or cementing the stone wall will help reduce their population. Birds, such as pigeons, like to roost on building ledges and under eaves. Since their droppings can become unseemly and possibly infectious, they should be discouraged from roosting there. Don’t bother with ultrasonic devices (birds can’t hear in the ultrasonic range) or plastic owls (the birds get used to them). Instead, obtain some spikes. These are stainless steel spines that prevent birds from landing on. After all who would want to land on needles?! This product is anchored in the areas where the birds roost to prevent them from roosting again. It is a permanent solution but it can cost from $2 to $6  a foot plus installation. If the birds roost under dormer eaves, then screen off the corners with galvanized quarter-inch hardware cloth. This procedure can also reduce the chances of squirrels chewing a hole in the corner.

A lighter form of habitat modification requires trimming back all tree branches within 4 to 6 feet of the roof line. As I tell my customers, once an animal finds easy access to your roof, it is just a short step away from looking for a way to get in. Overhanging tree branches are to squirrels and raccoons what an open door is to a thief. The tree branches are an invitation to check out your house. The same rules apply to shrubs. All shrubs should be allowed to grow no higher than two feet below the roof line. Don’t be fooled into thinking that trimming tree branches back will stop squirrels or raccoons from cruising your roof line. Squirrels and raccoons can climb gutters. The reason why you should trim the trees back is the same reason you lock your doors. It just makes it that much harder for them to access your building.

©2005 Stephen M. Vantassel

Unit 4B