Your chimney is prime real estate for wildlife
To a bird, raccoon, or squirrel, your chimney looks like a hollow tree: warm, sheltered, high off the ground, and safe from predators. Here on the Front Range we have all three plus the occasional starling colony, and every spring I pull nests and animals out of chimneys that one simple, free habit would have kept out. You can't do the removal yourself, that part is a job for a pro, but keeping them out in the first place is mostly free.
Here's what you can do from the ground to keep your chimney from becoming a wildlife condo, and how to tell when it's already occupied.
Ninety percent of the animal calls I get would never have happened with a good cap. The chimney is a hollow tree to a raccoon, and an open flue is an open door. Closing that door is the cheapest thing you'll ever do for your chimney.
- Adam, Owner, Adam Chimney Sweep
Why animals in the chimney are a real problem
It isn't just noise. An animal in the flue causes real trouble:
- A blocked flue. A nest or a stuck animal stops smoke and carbon monoxide from venting, which is dangerous the next time you light a fire.
- Smells and mess. Droppings, urine, and nesting debris stink, especially in summer heat, and can carry disease.
- Trapped young. In nesting season you may have babies that can't leave, which turns a simple deterrent into a removal job.
- Fire risk. A dry nest of twigs sitting in your flue is exactly the fuel you don't want near a fire.
Which animals end up in Colorado chimneys
Knowing the usual tenants helps you read the signs. Along the Front Range, the regulars are:
- Birds, especially in spring. Some build nests on the smoke shelf, others simply fall in and can't climb back out.
- Squirrels, which use an overhanging branch as a bridge and are quick, noisy, and prone to getting stuck.
- Raccoons, the big one. A female will treat an uncapped flue as a perfect den for a litter, and a mother raccoon with young is not something to tangle with.
One group deserves special mention. Chimney swifts are small birds that nest right inside the flue, and they're protected under the federal Migratory Bird Treaty Act, which makes it illegal to remove or disturb an active nest, as the U.S. Fish and Wildlife Service spells out. If you hear soft chittering high in the flue in summer, the right move is to wait until the young have fledged and left on their own, then cap the chimney so they can't return. A good pro knows the rules and the timing.
1. Check your cap from the ground, for free
The single best defense against animals is a chimney cap with sound mesh sides, and you can check yours without leaving the yard. Step back with a pair of binoculars and look at the top of the chimney. Is there a cap up there at all? Is the mesh intact, or is it torn, bent, or missing? A missing or damaged cap is an open invitation, and it's the first thing to fix. Never climb up to check it yourself, the view from the ground tells you what you need to know.
2. Know the signs you already have a tenant
Before nesting season, take a minute to check for residents:
- Listen at the fireplace for scratching, scrabbling, or chirping, which is loudest in the morning and evening.
- Open the damper a crack and shine a flashlight up, watching for nesting material or movement.
- Notice any new musty or foul smell coming from the firebox, especially in warm weather.
- Look for bits of twig, leaves, or droppings that have fallen onto the smoke shelf or hearth.
3. Free deterrents that actually work
Short of a cap, a few free habits make your chimney far less inviting:
- Keep the damper closed when the fireplace isn't in use, so any animal that does get in can't get into your living room.
- Trim back tree branches that overhang or touch the chimney and give squirrels and raccoons an easy bridge.
- Clear away anything at the base of the chimney that makes a tempting shelter or a climbing aid.
Trim the branch that touches the chimney and you cut off the squirrel's highway. Little free things like that keep animals from ever getting curious about your flue in the first place.
- Adam, Owner, Adam Chimney Sweep
What you should never do
When people think they have an animal in the chimney, the instinct is to act fast, and a couple of those instincts are dangerous:
- Never light a fire to smoke them out. It's cruel, it can trap and kill young, and a panicked animal can catch fire and start one in your home.
- Never seal the top while something is alive inside. A trapped animal will die in the flue, and then you have a far worse smell and a bigger removal problem.
- Don't climb the roof to handle it yourself. Wildlife is unpredictable and roofs are dangerous. This is where a pro comes in.
Please never light a fire to drive an animal out. I've seen the results, and it's bad for the animal and dangerous for the house. Call someone to get it out the right way, then we cap it so it never happens again.
- Adam, Owner, Adam Chimney Sweep
Why the cap is the fix that lasts
Every free deterrent here buys you time, but a proper chimney cap is the one thing that ends the problem for good, and it does more than block animals. A good cap keeps rain out of the flue, which is the leading cause of slow chimney damage in our freeze-thaw climate, and its mesh sides catch sparks and embers before they can drift onto your roof or a dry yard. So the same part that keeps the raccoons out is also guarding your chimney against water and your home against a stray ember. For one modest piece of stainless steel, it's the best-value upgrade most chimneys can get. And because it mounts up top out of sight, a good stainless cap shrugs off our hail, sun, and freeze-thaw far better than the flimsy galvanized covers, so it's the kind of fix you do once and forget.
When to call for humane removal
If you already hear or smell a tenant, the free deterrents are too late, and it's time for humane animal removal. We get the animal out safely, clear the nest, and install or repair a chimney cap so it doesn't happen again. Timing matters in spring, because removing a mother can strand babies, so our guide to birds and animals in the chimney walks through nesting season. If the smell is your main clue, our note on why a chimney smells helps you tell animal from moisture.
Frequently asked questions
How do I keep birds and animals out of my chimney for good?
A chimney cap with intact mesh sides is the answer. It's the one thing that physically blocks animals while still letting smoke out. Until you have a sound cap, keep the damper closed and trim back overhanging branches to make the chimney harder to reach.
There's an animal in my chimney, can I get it out myself?
It's best not to try. Don't light a fire and don't seal the top, both can be deadly to the animal and dangerous to you. Especially in spring there may be babies. Call for humane removal, then have a cap installed so it can't happen again.
Why do I smell something bad from my fireplace in summer?
A foul or musty smell in warm weather often means an animal, a nest, or droppings in the flue, made worse by heat and humidity. It can also be heavy creosote or moisture. A quick flashlight check and a sniff usually point you in the right direction, and a professional can confirm.
What time of year do animals get into chimneys?
Spring is the peak, when birds and raccoons are hunting for a safe place to nest and raise young. That's also the worst time to discover the problem, because removing a mother can strand babies. The best move is to check and cap your chimney in late winter or early fall, outside of nesting season.
Is it legal to remove a bird's nest from my chimney?
Not always. Chimney swifts and many other birds are federally protected while nesting, so an active nest can't legally be removed or disturbed. The safe, legal path is to wait until the young have left, then have the flue cleaned and capped to prevent it next year. A pro who knows the rules can advise on timing.
A few minutes with binoculars now can save you a spring full of scratching overhead. While you're looking the chimney over, run our free DIY chimney checkup too. Already have a guest? Get a free quote and we'll get them out and keep them out.
