FOR IMMEDIATE HELP
Q: How common is it to find mice in hoarder homes?
A: Extremely common. Rodents thrive in cluttered environments where there’s food, warmth, and places to hide. In hoarder homes, mice and rats can go undetected for years, leading to widespread contamination that affects air quality, structural integrity, and human health.
I was called by the Daughter, Mary, of a man ill in the hospital. She lived in another state, and after her mother passed away, she only saw her father on holidays. He always insisted on visiting her at her house. Mary had become concerned about him because she suspected he was drinking in excess.
After six years, they spoke less because the drinking had gotten out of hand, so their communication became less each year. Mary received a call from the hospital that her father was on his deathbed and wasn’t expected to get better.
So, Mary and Clark, her husband, rush to town to be with him. Her dad was lucid at times, but he mainly slept while they were in his hospital room. In his belongings, they recovered the house keys and decided to assess the condition of the house. She had been forewarned by a relative that it wasn’t taken care of.
She had trouble opening the door, and in frustration, she handed the keys to Clark to see if he could open it. Mary stood off to the side as he wrestled with the door, and finally, it swung open. Clark immediately remarked, Oh crap! As Mary moved to look into the house, she asked her husband why he had made that remark.
The porch stoop was slight, only about four feet square, and she came in behind where Clark stood, peering into the foyer. Mary took one look into the foyer and fainted, falling backward onto the sidewalk and lawn. Clark jumped to grab her, but he was too late. Reviving her, thinking she had to hurt herself, was moments away from calling 911 when she came around, but sobbing almost uncontrollably.
Please take me back to the hotel; I can’t; I don’t want to see anything more. Clark helped her into the car and returned to lock the front door. She couldn’t believe her dad was one of the worst hoarders she had seen. When she peered into the foyer, only about the first five feet were empty, and that led her eyes back to an eight-foot wall of trash.
This house was Mary’s childhood home. One where many memories of a happy middle-class family lived. This sort of thing didn’t happen to people or families like hers. That was always someone else’s problem, but now it was Mary’s. She grieved for her home and went through all the grieving steps. Then Papa died in the hospital, and Mary had to grieve for them both.
A few months later, she called our offices from her home and said she would be in town in a couple of days; would I meet her at the house?
Mary’s dad gave her the house and the insurance money. Still, the funeral expenses and the cleanup costs would be extensive and expensive.
Inside the Worst Mouse Infestation We’ve Cleaned: A Hoarding and Biohazard Case Study
Q: Can mice damage HVAC systems?
A: Absolutely. We’ve pulled mouse droppings and urine out of ductwork that sounded like sand. In this home, sticky mouse urine had built up so thick it coated the ducts like honey. We had to replace the entire system. Rodent waste in HVAC can circulate bacteria, allergens, and foul odors throughout a home.
As I stepped into the foyer, three mice greeted me, standing about a foot from the wall. I stood in place for just a minute, looking at the mice looking at me. I lifted one foot and, with my big work boot, stomped the floor.
Now, I fully expected those mice to scatter for the hills, scared to death. They weren’t. These mice glared right back at me without moving or flinching so far as I could see.
I don’t mind telling you that freaked me out. A horror film with a Steven King-esque type of feeling. Eventually, they turned and strolled into the pile of trash. I could swear I heard them laughing.
I looked around the house the best I could. I gained entry from the back door, but I couldn’t get too far into the kitchen.
I gave Mary my price, and she was shocked, but I told her I would need at least five, maybe six, 40-cubic-yard dumpsters, and even with my crew, it would take over a week to complete the job. She made one comment that I immediately caught. She said, “Perhaps I can sell it as is.” I told her I’d be happy to provide a price, but she’d need to give me a couple of days to do so.
I gave her a price and bought the home lock, stock, and mice with it. It took seven working days and five dumpsters to empty the house. And mice were running everywhere. When I had the HVAC system cleaned (which means vacuumed), the mouse poo sounded like sand being sucked out of the ducting.
To rehab the house, I stripped all the walls up to four feet, and we found a mouse nest between every other stud. We vacuumed out all the nesting materials, along with approximately 200 baby mice.
I got rid of the hoarding odor, but the mouse stench was still terrible. One of my workers stood on a small step ladder and was reaching above his head to pull one of the vents loose so we could look inside. He let out a yell with a big Oooooo as he got down from the ladder. I thought he stuck himself on an exposed screw or nail, but when I asked what was wrong. He said, I don’t know exactly, but there’s something like honey up on top of the duct.
It wasn’t honey, and it was on top of and inside of every HVAC duct. It was mouse urine, so thick it was like honey, and it was sticky. We ended up pulling and replacing all the HVAC ducting, and the interior of the furnace was steam-cleaned, along with the A-Coil. The support beam holding up the middle of the house had to be washed and steam cleaned—the sill plate on the perimeter of the foundation wall got steamed and sealed twice.
Every wall sill where we found mouse nests was sanded and sealed, as was the plywood subfloor. We’d locate the trails with blacklight, sand them down, and seal the entire subfloor.
While reading through this content, one might wonder how mouse urine could cause such extensive damage to a home’s HVAC system and structural components. To understand this, it’s essential to know more about mice’s behavior and their living habits. Like any urine, it can be rather corrosive if left in place.
Effective Mouse and Pest Control: The First Rule Every Homeowner Should Know
Mice are known for being skilled climbers and sneaky little creatures. They can easily enter homes through small cracks or openings in walls, floors, or roofs. A mouse can squeeze through a hole about ⅝” or 15mm in diameter. Once inside, they will typically seek out dark and warm spaces to build their nests, often in attics or crawl spaces where there is ample space.
The kitchen in this house was a nightmare. All the base cabinets were pulled. We saved the cabinet face and drawer fronts and replaced the boxes. We just replaced the bathroom vanities. But, under all the cabinetry was one or two nests.
I thought I would lose money on the project. Still, real estate values rose throughout the year we owned the property, and we were able to turn a decent profit. All the neighbors were grateful, and we were able to sell the home to a lovely family of four, just what the house was built for in the first place.
Written by Don M. McNulty © COPYRIGHT 2025 ALL RIGHTS RESERVED