There’s a scratching sound coming from the attic or an unpleasant smell from under your deck or droppings each morning on your front porch. You have become the reluctant host for wildlife.
This time of year, squirrels have made their way into attics to give birth and raise their young. Squirrels that were chasing each other around your yard in January and February are now parents. Squirrels mate twice a year with the second brood arriving in September. Females look for places such as your home for a nice warm, dry nursery. Unless you can catch the squirrel before she has her young, you need to wait 12 to 14 weeks after she has given birth to evict the family. By that time, the young are weaned and can live on their own. The best eviction method is a one-way door. It allows the squirrels or any other unwanted wildlife to leave the space but not re-enter. Once you know that everyone has left, the door can be removed and the area repaired.
It’s always a good idea to inspect your home yearly looking for places where wildlife can make themselves at home. The prime places to look are: openings in foundations, an uncapped chimney, soffit and eave vents that aren’t covered with heavy duty wire mesh screen or the screen has been damaged and locations on the roof or siding that may collect snow or water rotting the wood making it easy to chew and dig through.
Other steps you can take to help keep squirrels and other wildlife out of your home are: remove tree limbs that overhang your roof, don’t feed birds or squirrels or at least clean up under the feeder daily, place metal barriers on wires, trees or tree limbs to prevent roof access, block access under decks and porches, screen vents and seal openings in the foundation and between porches and houses. You can try repellants but must understand that the repellant must be reapplied periodically and the active ingredient in the repellant must be changed periodically. Wildlife like humans can become accustomed to smells so, if you notice the repellant doesn’t appear to be working, change it out for a different one. Read the ingredients on the label to be sure you are getting a different repellant (i.e. hot pepper versus egg solids versus Thiram®) not just a different manufacturer.
Mice enter your home through holes in the foundation of ¼” diameter and other openings. Look for foundation cracks, other openings such as where pipes or conduit breech the foundation. The easiest way to close these access points is to fill them with steel wool. You can secure the steel wool with a spray in foam insulation. Do not use the insulation alone as mice like to chew through it.
Skunks, raccoons and rats may den under your porch, deck or shed if you do not have it screened off. Fasten heavy duty screen (hardware cloth with <1/4” openings ) to the side of the deck and then form an L shape with the bottom part of the L pointed away from the deck preferably buried 1’ deep and out 1’ out from the deck or lay and fasten the screen on top of the soil to keep them from digging.
Bats are still in hibernation until May but will then start looking for openings to your attic or by your porch. Fill openings between the house and porch with insulation or put screen over vent openings to prevent access.
By Sharon Bokan, Colorado State University Extension Boulder County. For more help with wildlife issues, contact the CSU Extension Wildlife Masters at 303.678.6238.