Are you hearing rustling noises in the bathroom and think there is an animal in the vent? Or, maybe you’re noticing a house sparrow or starling coming and going from a vent? Perhaps, a little bit of nesting material is sticking out of a vent? You’re not alone. Lots of people don’t realize that many of their home’s exterior vents—that exhaust appliances like dryers and furnaces and the different fans and vents that exhaust attics, bathrooms, microwaves, and stoves, —are viewed as prime real estate by these two common cavity nesting birds, unless they have covers on them. And be aware that both of these bird species are adept at using vents that may seem protected by louvers or a hanging door that flips up when the fan is turned on. So, now what?
Identify the nesters…
First, be sure that the bird in your vent is either a house sparrow or a European starling. Almost all other birds are protected by the Migratory Bird Treaty Act and cannot be moved, nor their active nests disturbed. (In this case, you will need to wait until the eggs have hatched and the birds have left; then you can seal off the entry point with a vent cover to prevent future nests.)
If you are certain that it is either a house sparrow’s or European starling’s nest, and it is just getting started—meaning that no eggs or young are present—you may remove the nesting material and seal up the opening. The bird will then look for another place to nest, so while you are taking care of the opening, be sure to look for other vents that may need covers.
Only when the nest is a safety hazard, should baby birds be moved to a substitute nest. J. Griffin
What if the nest already has young?
If the nest is already occupied by nestlings, you’ll want to prevent injuring or orphaning them, so the situation calls for a little more patience. Unless the nest is creating a hazard—as a dryer vent nest might—wait for the young to leave the nest before removing it. The young may be a bit noisy, but it won’t be more than a few weeks until they are able to fly (10-14 days for house sparrows; up to 21 days for starlings), and then you can install a cover to keep the problem from happening again.
What if the full use of the vent is needed sooner…
Safety must come first, of course. If a vent nest cannot be left in place long enough for the young to leave the nest on their own, you can do a humane eviction that gives the nestlings some chance of surviving and fledging. Here’s the process:
- Select a mounting place as near to the and as high as the original nest as possible, sheltered from weather and not in direct sun.
- Attach a substitute nest using a small wicker basket, or take a plastic gallon jug and cut a U-shaped opening in it for the entrance. Poke a few holes in the bottom of the jug to allow for drainage should it rain.
- Transfer as much of the actual nesting material as possible into the substitute nest, and carefully place nestlings into it.
- Retreat to a place from which you can observe the nest, while being far enough away that the parents will feel secure attending to their young.
- Watch for the parents to return. If they have not begun feeding the young within a couple of hours or so, contact a wildlife rehabilitator to see about their care.
Remove all of the nesting material before covering vents. J. Griffin
What makes an effective vent cover…
Most hardware stores sell commercially made vent covers for dryer and bathroom exhaust vents. Dryer vents need to be cleaned to prevent lint buildup and the protective cover selected must be of a type that allows the vent to be accessed and cleaned. Attic and stove exhaust vents, which vary more in size and shape, can be protected by attaching a common material also found at your hardware store18-22 gauge ½-inch square galvanized hardware cloth. Attach the wire so that any louvers or flip doors can open to allow easy airflow. Make sure to remove all of the material in the vent duct to make sure the vent will work as designed. If there has been heavy nest building or long-term occupation the vent may be completely occluded and in this case may require a professional to clean it or replace it entirely.