Rats or Mice in Your Home? Here’s How to Keep Them Away
ORIGINALLY FROM NOVEMBER 2020, UPDATED DECEMBER 2024
As the season shifts towards cooler temperatures, the rodent activity around your home and garden is likely ramping up. This isn't a pleasant topic, but it’s important to cover. Rodents seem to be the number one pest issue I see folks having, especially during this time of the year. Are you faced with a rodent situation too?
If so, there are four steps to address your current rodent situation and prevent rodents from invading your home: identify, secure, exclude, and control. Let’s dig into each of these so you feel confident keeping rats and mice away… for good.
1. Properly Identify Whether You Have Rats or Mice
It’s important to know what you’re up against. Is it a common house mouse, a roof rat, or a Norway rat? There are a few differentiating factors, so let’s go over them.
House mouse
House mice are tiny, weighing only ½ an ounce! They are about 5-7 inches long including their 3-4 inches tail with a small head, pointy snout, large ears, and small feet. You can usually distinguish them from their light brownish to grey coloring. Their droppings are small, about the size of a sesame seed.
Roof rat
Roof rats have a somewhat slender, sleek body and weigh about 5-10 ounces. They have a pointed snout, a long tail, and large ears. A roof rat’s droppings will be larger than a mouse's, similar to the size of a grain of rice.
Norway rat
Norway rats have a thicker, larger body. They weigh between 7-18 ounces and have a shorter tail and snout with smaller ears. Their droppings are a bit larger than a grain of rice.
For a wonderful resource on rat identification in California, check this out.
2. Secure Your Space
Food on the counter and crumbs under the table are an invitation for mice and rats.
Clean up food
Secure food in jars and containers
Secure compost bins and garbage cans
Remove food sources
Fix any water leaks
Store pet food in galvanized cans with lids
3. Keep Them Away
To keep rats and mice out of your home, be diligent and seal up any possible points of entry. A mouse or a young rat can fit through a hole ⅜ of an inch… That’s small!
Go room by room to search behind your appliances, inside cupboards, and under cabinets to find ways they are getting in. Walk around the perimeter of your home and check door sweeps, weather stripping, and foundation vents. Once you find evidence of rodents finding their way in, address it accordingly.
Use ¼ inch hardware cloth, sheet metal roof flashing (cut to fit around pipes), or copper wool to close off entry points. These are the only materials that rats can’t chew through!
4. Consider Population Control
The reality is that if you think you have one rat or mouse, you usually have many.
The best, most effective way to manage these rodents is with kill traps – snap traps, interior electric traps, and exterior CO2-style traps. When used properly, these are the most humane way to manage rodent populations. It’s a good idea to saturate an area with traps, placing 12-16. I understand this is a bit challenging for the average person, so start with no less than 2-4 snap-style traps in an area, one of the electric traps per room, and one CO2-style trap per outside zone.
When you introduce traps to the area, keep in mind that rodents are suspicious of new things and won't automatically feed off of the trap just because you set it out. I recommend you pre-bait the snap and electric traps without setting them. Allow the rodent to become familiar with this feeding station. After they have fed off it a few times, set the trap. Once you trap a rodent, dispose of it in a sealed bag and place it into the garbage. Bait and set your trap, and repeat.
The best pest baits
What should you use as bait for the traps you set? Well, many people swear by peanut butter. It’s not my first choice since it dehydrates and shrinks, allowing the rodent to lift the bead of peanut butter off the trigger without setting it. Successful for it… not for you or me.
I prefer using a tiny piece of a chewy granola bar, a Fig Newton, cat or dog kibble, or whatever the rodents got into. Rats also love meat sticks and any sort of chocolate-nutty-chewy candy. I also heard that Nutella is a popular bait option.
The idea is to be open to changing it up if you find that one bait doesn’t work.
When I had a mouse infestation in my San Francisco flat, it took me 4 days to find a bait the mice would go for. I tried everything. They ended up going for my roommate’s herbed tofu cream cheese. Who knew that the mice in San Francisco were vegans? I caught 22 mice that night once I found the right bait. The minute I heard the trap snap, I would dispose of it and repeat. I had no idea the magnitude of the situation. I then found the point of entry and sealed it up. No more rodent problems!
Why to Avoid Rodenticides or Poison Baits
Something that isn't explained to gardeners and consumers like you is that rodenticides are not as effective as kill traps, are very dangerous, and are lethal to non-rodents.
Here are just a few reasons to avoid rodenticides:
It can take 2-14 days for the bait to kill the rodent
The rodent can still reproduce
Secondary kills – if a dog, a cat, or a raptor eats that rodent and there’s enough bait to kill that animal – can occur
Also, these baits are intended for the rodent to feed off of it multiple times and for it to be its only food source. If there is other food around, it can dilute the bait and make it less effective.
Although poison baits are marketed as an easy solution, they’re the least effective way to manage your pest problem. Just think about what happens if the rodent dies in the wall of your home… There’s a better solution to rid your home of mice naturally.
Ways We Can Grow Together
Rodent problems aren’t easy and can be extremely frustrating. Sadly, there isn't an easy one-step process to get rid of or prevent them. It takes resourcefulness and patience but, in the end, your home will be mice-free because of your diligence.
If you have any additional questions about rodent or pest management, please don't hesitate to send me an email. Or better yet, join one of my upcoming gardening and pest webinars where you can ask your questions live.