Experts warn rodents nesting in your HVAC unit can spark fires, cause damage and even spread hantavirus — here's how to keep your home safe

According to the Centers for Disease Control and Prevention (CDC), people can contract hantavirus by breathing in air contaminated with fresh mouse or rat urine, droppings or nesting materials from an infected rodent.

Hiding in an HVAC

HVAC maintenance companies in other states have seen an uptick in unexpected guests in cooling systems. CBS News spoke to Steve Akian of Akian Plumbing, Heating and Air Conditioning, based in Watertown, Massachusetts, who said “as soon as temperatures climb, so do the number of calls coming in.”

On one such call, Akian told CBS he found several baby squirrels nesting in a cooling unit. “I think we’re going to see more of that this year due to how cold the winter was. They find shelter in these systems and the wires sometimes are made out of rice resin, so the mice will chew through it,” he said.

Rodents in a cooling system can cause damage and even pose a fire risk, the technician added. “The system could trip, it could sort of have erratic behavior, like turning off and on, that’s what we were experiencing at that client’s house. Or worse, it could potentially cause fires when we’re dealing with electrical [damage],” Akian said.

Moneywise reached out to both companies for comment — Air Bear Heating and Cooling and Akian Plumbing, Heating and Air Conditioning — but did not receive a response.

How to keep your home (and family) safe

To minimize the risk of rodents, most experts recommend getting your air system serviced twice a year. You can also use foam insulation to seal holes in the home and block rodent entry points. Mark Geisel of Envirotek told WMBF News to clean up droppings as quickly as possible, but not with a vacuum.

“Wet the area down and then sweep it up. That way it doesn’t crumble and have the airborne disease,” he said.

Geisel advised wearing a mask when cleaning but said it’s best to let a professional handle it. Always have Lysol, gloves and bags for quick disposal on hand when dealing with droppings.

It’s not just cooling systems that critters can infiltrate. Rodents can also compromise wiring, causing electrical issues, or find their way into vehicles. Just as you should schedule yearly or twice-yearly HVAC maintenance, invest in the same upkeep for your electrical systems, vehicles and pest control.