Swifts have small nests that pose no safety or health hazard, and are composed of twigs and their fire resistant saliva. The only time you will really notice them is when they have babies begging for food from their parents. This is the loudest during their last two weeks in the chimney.

Chimney swifts are present in North America only during the warmest months of the year. By fall, they've migrated back to South America. To muffle the noise, place a thick piece of Styrofoam across the fireplace opening until the babies fledge. Once they are gone, place a wire screen across the top of the chimney to prevent further nesting.