ONETIME- 'Possum hunt: Rodent-proofing your home
One time, I got a call from a lady who had been hearing loud, unexplained noises underneath her house. She also said that whenever she cut the heat on, her house would reek from this godawful smell.
I took a look around. It was fall, and she had a problem with field mice trying to come in and stay warm, and they were also bringing along their predators after them.
I started seeing dead mice all under the house and picked them up for her. But in some ductwork, hanging half in and half out, was this opossum, very dead.
It had tried climbing into the main shaft for the heating and air conditioning system. With its front and back legs dangling, it couldn't grab onto anything. It couldn't escape, had died, and whenever the heat came on, she was getting waves of putrid opossum funk filling up the house.
The best thing to do about rodents is take preventative steps. The homeowner needs to walk around the house and every crack or crevice that needs to be sealed up should be sealed.
When you have water pipes or electrical lines go through your foundation for your air conditioning or whatever, very often the hole is bigger than the wires or pipes but was never sealed up. So seal them up.
A good product to use to seal places like that is steel wool. Rodents can't chew it: it tears their teeth up. Stuff it in there, and put caulk around it or use spray foam in a can. Don't just use foam in a can by itself– they'll eat right through that.
Foundation vents on older homes have old screens that have rusted away and they leave areas where the animals can slip in. You can either get them re-screened or replace them with a device called a Tent Vent that automatically opens. It has a screen on the front and on the back so you're sealing it with two separate ones.
Make sure that your chimneys are capped off to keep insects and rodents out because they will climb downspouts and things to get into your attic.
Check your gable ends where you have louvered vents from the inside to make sure that the screen is intact. The mice will rip a screen to get in.
And cats aren't always dependable. I've seen some that were as afraid of mice as mice are afraid of cats.