Q. It seems we have a family of starlings nesting in the roof soffits on our house. My husband was able to find the hole where they are entering. Can we just seal that up to keep them out or will they peck it open again?

A. You don’t want to block the opening that the starlings are using unless you are sure the young have left the nest. You don’t want to exclude the parents from the nest when young are still present or the young will die (and then rot and smell). If starling parents are blocked from their young, they may try to reopen the hole. Once the young have fledged, the opening can be sealed, screened, or blocked. If the entrance is not closed, starlings often return to use the same cavity as a nest site for their next brood. (Only certain methods should be used to seal off dryer vents because the vent could become blocked with lint and become a fire hazard.)

Most people don’t think of starlings as being cavity nesters. By cavities, we mean any small, dark opening into a space that can simulate a tree hole in nature. In commercial sites, starlings are happy to nest in cracks in buildings, on building ledges, on roof beams in warehouses, and on shopping center signs. In residential areas, the cavities starlings choose may be bird houses, or openings on your house such as vents, openings under a roof overhang, chimneys, or holes in gutters.

Our more common cavity nesters in and on homes are house sparrows, finches, Carolina wrens, and woodpeckers. Starlings, though, are very adaptable and very aggressive in outcompeting other birds for cavity nest sites. Starlings will even crawl through a small opening on a building to gain access to a larger cavity in a wall or roof where they will build a nest. When nest sites are limited, starlings can outcompete and reduce the population of native songbirds.

A starling’s nest is a sloppy accumulation of dried leaves, stems, grass, and twigs in which 4 to 7 eggs are laid. Both parents rear the young, which hatch out in 11 to 13 days and leave the nest at about 21 days. But starlings often have at least two broods a year so it may be difficult to find a time between broods when young are not present and the opening can be sealed.

It’s not healthy to have birds nesting on your home for many reasons. Their droppings smell bad, are slippery to walk on, and under certain conditions, a buildup of droppings can promote the growth of the fungus that causes histoplasmosis, a disease that affects people. Bird nests usually contain some level of blood-feeding parasites such as bird lice, mites, or ticks. These parasites feed on the birds but once birds have left a nest (or been sealed out), there is a risk that the parasites in the nest could move into living areas in your home where they could bite your family.

For this reason it’s not enough to simply seal the opening. It’s important to have a complete bird management program that also includes cleaning up the nest site and treating the area with pesticides to kill parasites. If you don’t want to do it yourself, contact our pest control experts at Colonial. We can do all that, and can also do bird-proofing of your home to block the opening and seal other openings that the birds might use. We are certified and licensed to do bird work (we’ve been doing it for 25 years!) and bird-proofing is our specialty. Give us a call today!