Scratching, chirping, or fluttering sounds from the flue are one of the most common calls we get in Lexington, KY once the weather turns — and how you handle it depends on which animal it is, because one of the likely culprits is federally protected.
What animal is actually in my chimney?
Chimney swifts, raccoons, and squirrels are the three most common, and they sound and behave differently: swifts make a soft chittering sound and nest in a loose twig cup stuck to the flue wall, raccoons are heavier and move at night, and squirrels are active during the day and often heard scratching near the top.
Chimney swifts are a federally protected migratory bird under the Migratory Bird Treaty Act — it’s illegal to remove, disturb, or block an active swift nest with eggs or young inside, and a capped or swept chimney with swifts nesting in it can mean an expensive delay if the work has to stop mid-project. Raccoons and squirrels carry no such protection, but a mother with young still needs to be handled carefully to avoid orphaning babies inside a flue you can’t easily reach.
What should I do if I hear something in the chimney?
- Don’t light a fire — smoke won’t remove an animal reliably and can injure or kill it, plus a panicked animal can knock debris down into the firebox
- Don’t cap the chimney yourself while you hear activity — you may seal an animal inside, or in a swift’s case, break federal law
- Call for an inspection to identify the species and whether young are present before any removal or capping happens
- Once the chimney is confirmed empty, have a cap installed to keep it that way
When is the right time to cap a chimney against animals?
Fall, after chimney swifts have migrated south for the winter, is the safest window in Lexington — capping now avoids the nesting season entirely and keeps raccoons and squirrels from moving in to den for the winter. A properly fitted cap with a mesh guard is the permanent fix; installation runs the same range as a standard cap replacement, typically $200-$600 depending on flue size and cap style, covered in more detail on our chimney cap page.
Common questions
Can I just put a cap on now and deal with it later?
Not if you hear activity. Confirm the chimney is empty first — sealing an active nest or den traps the animal inside, which creates a bigger problem and, with swifts, a legal one.
Do chimney swifts come back to the same chimney every year?
Often, yes, if the chimney stays uncapped and accessible. That’s exactly why capping after they migrate in fall — before next spring’s nesting season — is the effective long-term fix.
Will a cap damage or block normal draft?
No. A correctly sized cap with mesh sides is designed to keep airflow while blocking animals, rain, and debris — it’s standard equipment on a functioning chimney, not an obstruction.
Not sure what’s making the noise, or ready to have a cap installed before winter? Call or text (859) 310-1209 and we’ll identify it and give you a straight answer on timing. Chimney swifts and their federal protection status are documented by the U.S. Fish and Wildlife Service.
Last updated: September 25, 2026