The text comes in at 7:40 on a Saturday morning: "Half the maple out front went dark last night, and there are little bulbs all over the mulch." You wrapped that tree nine days ago and it tested perfectly. Nothing failed. A squirrel found it.
I have been installing Christmas lights professionally since 2014 and run a 43,000+ member installer community, and squirrel damage shows up in that group every November like clockwork. It is one of the most common mid-season callbacks that has nothing to do with your workmanship—and one of the easiest to turn into a customer for life.
Why do squirrels chew Christmas lights?
A squirrel's front teeth never stop growing, so it gnaws on hard things to keep them worn down. Light wire happens to be the right diameter, and you just strung it along the exact branches, fence tops, and gutters the animal already runs every day. Bulbs get it too: to a squirrel, a bulb looks a lot like a nut, and installers regularly find them plucked from the socket and dropped at the base of the tree.
You will hear theories about wire insulation tasting good. I cannot tell you what is in every wire jacket, and it does not change the plan. Squirrels chew wire of every kind, so you manage the route and the response time, not the recipe.
Three conditions make a property a repeat target:
- Food nearby. Bird feeders, pumpkins, corn stalks, and nut trees pull squirrels straight into the display.
- Bridges. A limb touching the roof, or a run that crosses from a tree to the house, is a highway.
- Slack. Drooping wire and loose loops are easier to grab and hold than a tight, clipped run.
How do you tell squirrel damage from a blown fuse or a bad socket?
Look before you touch anything. Squirrel damage leaves evidence that an electrical fault does not: a wire cut clean through at an angle, insulation stripped back to bare copper, empty sockets, or bulbs scattered on the ground. It also clusters in predictable places—the first branch crotch on a wrapped tree, the top of a fence, the spot where a limb meets the gutter.
| What you see | Most likely cause | First move |
|---|---|---|
| Wire severed or stripped, bulbs on the ground | Squirrel | Unplug, cut out or swap the section |
| Empty sockets, wire intact | Squirrel carrying off bulbs | Check sockets, replace bulbs |
| One whole mini strand dark, no visible damage | Fuse in the strand's plug | Check the fuse, then the strand |
| Dark section of C9, no visible damage | Socket or wiring—rarely a fuse on pro C9 LED | Trace the socket wire and connections |
| Everything dark, GFCI tripped | Moisture reaching a connection or exposed copper | Find the water or the bare wire |
That last row matters. Chewed insulation leaves bare copper, and bare copper plus rain is one of the faults that trips a GFCI. Splitting the run will not fix it; you have to find the damage. Never test or replace the homeowner's GFCI yourself—that is a licensed electrician's job. Our guide to a GFCI that keeps tripping covers the full hunt.
If there is no chew evidence and a mini strand is dark from end to end, rule out the fuse first. This video walks through it, and the written steps are in how to change a fuse in mini lights.
For every other dark-section scenario, work the sequence in how pros troubleshoot Christmas lights.
How do you fix Christmas lights a squirrel chewed?
Unplug the run before your hands go anywhere near it. Chewed wire means exposed copper on a live circuit. Then match the fix to what was damaged.
- Unplug and photograph. One photo of the chew marks for your records and one for the customer. It shows the cause without a debate.
- C9 run on socket wire: cut out the damaged span with side cutters. Put a female slide-on plug on the end that still feeds from power and a male plug on the other end, then plug the two together. If the run is chewed in several places, swap in a pre-bulbed spare from the truck. Building runs this way is covered in C9 stringer wire and custom runs.
- Mini lights on a tree or bush: do not splice a mini strand. Unwind the damaged strand, plug in a new one, and re-wrap at the same spacing. The technique is in tree wrapping and branch wrapping.
- Custom cord: SPT-1 zip wire is cheap. Cut out the bad section and add new zip plugs, or replace the cord. See custom cords with vampire plugs.
- Missing bulbs only: check each socket for cracks, then thread in new LED bulbs.
- Re-seat the connection. Elevate it off the ground, sockets facing down, with a drip loop. Do not tape or seal it—tape traps water. The details are in weatherproofing connections.
- Plug in, confirm, and send the after photo.
Never twist bare wires together and wrap them in electrical tape. That is a failure waiting for the next rain, and tape does not belong on the truck anyway. If you are deciding whether a damaged strand is worth saving back at the shop, use the replace-versus-repair guide.
What should be on the truck for a squirrel callback?
The fix is only fast if the parts are already with you. A second trip to the shop turns a 15-minute stop into an hour and a half.
| Item | Why it is there |
|---|---|
| Spare mini strands in each color and spacing you installed | Trees and bushes get swapped, not spliced |
| A pre-bulbed, pre-clipped C9 spare run | Replaces a section chewed in several places |
| Male and female slide-on plugs | Rejoins a C9 run after you cut out the damage |
| Loose C9 LED bulbs in the customer's color | Refills sockets a squirrel emptied |
| SPT-1 zip wire and zip plugs | Builds a new cord on the lawn in two minutes |
| Precision cutters and side cutters | The only cutting tools the repair needs |
Keep it all in the fisherman's vest or one labeled tote so any crew member can run the call. The cutters I carry are on the installer tools list, and extra Tuff Clips ride along for any clip a squirrel knocks loose while it works.
Can you stop squirrels from chewing Christmas lights?
You can lower the odds. You cannot get them to zero, and any installer who promises a squirrel-proof display is setting up an argument for December. Here is what moves the needle, in the order I would do it:
- Pull the slack out. Tight wire on enclosed clips is harder to grab than a drooping loop. On trees, run the cord up the trunk snug instead of letting it hang free.
- Move the food. Ask the homeowner to relocate bird feeders and take porch pumpkins and corn stalks away from the lit areas for the season. This one change does more than any product.
- Break the bridges. Do not run wire from a tree to the roofline, and note any limb that touches the house so the homeowner can decide whether to trim it.
- Redesign the repeat spot. If the same branch gets hit twice, stop wrapping that branch. Shift the wrap to the trunk and the main limbs.
- Treat deterrent sprays as a maybe. Homeowners will ask about hot-pepper sprays. Results in the field are mixed and rain washes them off, so I never build a service promise on one.
Leave trapping and removal to licensed wildlife control. Rules vary by state, and it is not what the customer hired you to do. Skip poison and mothballs entirely.
Who pays when squirrels damage a professional install?
On a display you installed, you fix it at no charge. Service all season is part of what the $8–$12 per linear foot price already covers, right alongside takedown. The homeowner did not buy wire and bulbs. They bought the feeling of pulling into the driveway with the grandkids in the back seat and the whole house glowing, and a dark tree takes that away until you show up.
Take the customer from the Saturday text. The job was 120 feet of roofline at $10 per foot ($1,200), a 12-foot maple at $45 per foot of height ($540), and a 24-inch wreath at $107 installed, for a total of $1,847. The squirrel fix costs you two spare mini strands and about 20 minutes on a route you are already driving. Arguing over a service fee puts next year's $1,847 renewal at risk to recover a fraction of it.
The reply that keeps the customer:
"Thanks for the heads-up. Squirrels found your lights—it happens every season and it is covered. We will have the tree glowing again by tomorrow evening, no charge."
Showing up fast and cheerful for a problem you did not cause is the most magical thing a service company can do. The full policy is in how pros handle service calls. Put animal damage in writing before the season the same way you handle storms in the wind-damage playbook, and spell out what is covered in your guarantee and contract.
The exception is a display you did not install. A homeowner who calls about chewed lights from another company or a DIY job gets a standalone service price of $75–$200—and often becomes next year's full install.
Next step: build the repair kit before the next text comes in. Restock spare tree strands from the 5mm wide-angle LED mini lights and loose bulbs from the C9 LED collection so every truck can close a squirrel callback in one stop.
Related Guides
- Christmas Light Service Calls: How Pros Handle Callbacks
- Troubleshooting Christmas Lights: How Pros Diagnose and Fix Common Problems
- How to Quote Christmas Light Tree Wrapping
- Christmas Light Warranty and Guarantee: What Pros Promise
Frequently Asked Questions
Why do squirrels chew Christmas lights?
Squirrels gnaw to wear down front teeth that never stop growing, and light wire runs along the branches, fences, and gutters they already travel. Bulbs are about the size of a nut, so squirrels also pull them from sockets and carry them off.
How do I keep squirrels from chewing Christmas lights?
Pull the slack out of every run, move bird feeders and pumpkins away from the lit areas, avoid running wire from trees to the roofline, and stop wrapping any branch that gets hit twice. These steps lower the odds, but no method makes a display squirrel-proof.
Can chewed Christmas light wire be repaired?
On a C9 run built on socket wire, yes: unplug it, cut out the damaged span, and rejoin the ends with a female and a male slide-on plug. Mini light strands should be replaced, not spliced. Never twist wires together and wrap them in electrical tape.
Are chewed Christmas lights dangerous?
Chewed insulation exposes bare copper on a live circuit, and moisture on that copper can trip the GFCI. Unplug the run before touching it and repair or replace the damaged section before plugging it back in.
Should I charge the customer for squirrel damage?
Not on a display you installed. Season-long service is included in the $8–$12 per linear foot price, the same as takedown. Charge a standalone service price of $75–$200 only for lights you did not install.
About the Author
Jason Geiman has been installing Christmas lights professionally since 2014 and is the founder of ChristmasLightsHQ, the resource for professional Christmas light installers. He runs a 43,000+ member installer community—join the conversation at christmaslights.io/group.