NUISANCE WILDLIFE

Wildlife management pertains to several different areas. They are identification, exclusion, and trapping/control. Because the laws vary concerning trapping/control, we will not discuss these topics, with the exception of the deer mouse. For additional information concerning trapping, see your local wildlife control office. For assistance on identification, see Pestdude's WILDLIFE IDENTIFICATION page.

EXCLUSION TECHNIQUES

This page mainly deals with exclusion techniques.

Bats

Bats will enter a structure for two reasons.
  1. To nest
  2. To rest the during the day
Bats will usually enter the attic or other upper location. An inspection will determine the extent of the infestation. Bats will leave a large amount of droppings where they nest and their will also be an acrid musty odor from their urine. Bats that only use a location for resting will leave much less droppings and urine behind. In these locations, the reason the bats are there is because, while they were feeding at night, either daylight came while they were away from the nesting area or the weather turned bad.
Bats will have babies during June and July in their nesting areas. Some states require that no exclusion work is done during June through August because the babies will then get trapped and die. Killing bats is illegal in some states.
Bat Exclusion work involves:

  1. Locating the main and secondary entrance points
  2. Locating all other opening 3/8 inch or larger
  3. Sealing all openings (such as around gabled peaks, gabled and soffet vents, cracks around facia boards, chimney and other flashings, etc.) with either foam, steel wool, or copper wool, except for the openings that the bats are currently using
  4. Installing bat doors over the openings that the bats are using, keeping them in place for at least a week, if weather is good
  5. Removing the bat door eventually and sealing these openings
  6. Consider installing chimney caps to keep them from entering through the chimney.
Bat door are nothing more than taking screening (nylon screening used in windows works well) and attaching a piece 3 to 5 times larger than the opening over the opening, attaching only the top and side, letting the bottom remain at least 6 to 12 inches below the opening and unattached. The bats, when they leave at night to feed, will hit the screening and fall through the opening at the bottom. When they return, they will try to enter the opening, following their scent, but will not be able to reenter and will go elsewhere.

Remember to seal all other openings because the bats will attempt to follow their scent to other openings to get in.

Squirrels

Squirrel exclusion involves first locating how they are entering the structure. Areas to look at include:
  • Utility line entrances
  • Drain pipes
  • Uncapped chimneys
  • Attic or basement vents
  • Also look for overhanging tree limbs that allow squirrels to enter the structure.
All openings should be sealed with foam, steel wool, or copper wool. Also, for homes that are unoccupied, a liberal sprinkling of naphthalene flakes may help to repel squirrels.

Deer Mice

All openings smaller than 1/4 inch should be sealed with either foam, steel wool, or copper wool. Deer mice can also be taken care the same way as house mice. See Pestdude's RATS AND MICE page for more details.

Raccoons

Raccoons raiding garbage cans can be discouraged be storing garbage in tight lid containers and should either be kept in "garbage sheds", closed garages, or be wired secure because raccoons will tip garbage cans over.

Chimney caps will help prevent raccoons from entering chimneys. Be sure to properly install these caps because improperly installed caps can cause a fire or toxic gas hazard.

After you are sure raccoons are removed from the structure, then sealing all entrance areas should help keep them out. The use of naphlalene flakes in enclosed areas may also help keep raccoons out.

Moles

Moles feed on grubs, worms, ants, and other arthropods found in the soil. Pesticide applications for these food sources, although may not be effective in the control of moles, sometimes are. The only truly effective method of control is trapping. Because of laws pertaining to wildlife trapping and the special types of traps means you should seriously consider hiring a professional to do this.

Skunks

To determine where skunks are entering under a structure, the use of sand, dust, or flour, sprinkled around the structure, can help determine where the skunks enter. Once located, the use of a hardware cloth "door" where the skunk opens the hinged door upon leaving but cannot open it to return, will help get the skunk out of the den. Then, the installation of hard wire (chicken wire) fencing should keep them out.

Groundhogs

Groundhogs are controlled by one of three methods, fumigation, trapping, or by shooting. These all require a wildlife management professional.

See also: HOW TO CHOOSE A PEST MANAGEMENT PROFESSIONAL

If you have any questions, please ask Pestdude!