Before you can get rid of mice, you need to realise they’re in your home or business in the first place.
The most clear cut sign of a mice infestation is, of course, seeing one, but since mice are cautious, nocturnal creatures, they can live in your house for months or even years without ever showing themselves.
Unfortunately, by the time you’re seeing them, you’re already too late. There’s never just one mice, so for every one you see there’s almost always a whole family you’re not.
You’re more likely to hear mice than see them. When lying in bed you might hear the telltale skittering and scraping sounds behind walls and beneath floorboards that tell you mice are about. If you make a noise, you’ll hear them stop for a moment, before resuming once they feel safe again.
Finally, you might smell them. Mice urine has a strong ammonia odour, which is strongest around their nest or their preferred feeding spots. Mice are incontinent and spread urine wherever they go, which can build gradually into a strong odour.
It takes quite a lot of urine to produce a strong smell, so if you can smell mice, you need to act immediately because you likely have a severe mice infestation.
Evidence of a Mice Infestation
Seeing, hearing or smelling mice might give away an infestation, but it’s more likely that you’ll spot the evidence they leave behind them, such as their droppings.
Mouse droppings are black or dark brown and about the size of a grain of rice, hence our favourite phrase, “if it’s rice, it’s mice”. Any larger than that, about a peppercorn or above, then you’re dealing with rats.
You’ll often find droppings beneath kitchen units, in cupboards, on surfaces or even inside toasters and grills where they feed on crumbs or fat.
If mice don’t have existing routes around your home, they’ll start making them. Mouse holes are nothing like the neat arches from Tom and Jerry; they’re small, rough openings that are smaller than you might expect. Mice only need a hole the size of a ballpoint pen to be able to squeeze through.
Mice are greasy little creatures, and when they squeeze through their holes or scurry along skirting boards they’ll leave their residue behind them. As dirt sticks to the grease, you’ll start to see dark marks form along their favourite routes, known as smearing. The presence of smearing is an easy way to tell if a hole was preexisting or made by mice.
Gnawed food bags
If you go to pick up your cereal in the morning and a bunch spills out a hole onto your counter, then it’s time to give us a call because you have a mice infestation.
Bags of rice, cereal, flour, pet food and so on are easy targets for hungry mice. Bags of pet food stored away in attics or basements are especially ideal, as they let families of mice feast without being spotted for weeks or months. This is why we always recommend to store all food in gnaw-proof containers.
If you’re still not sure if you have a mice infestation, or want to verify the extent or areas of infestation, here a couple of DIY tests that anyone can do.
Spreading flour or talcum powder overnight on surfaces or floors where you suspect mice have been will reveal their trails of footprints. This can help you determine how many mice there are and what routes they’re taking around your home, or whether you actually have rats.
Their prints are around half a centimetre or a ¼ inch in size, and are so small they look like little scattering of dots rather than clear footprints. Rat footprints are twice as big at least, with clearly defined footprints with larger hind feet than front.
Professionals use invisible UV tracking powder instead of flour, but the technique remains the same and is an essential part of the diagnosis process for mice infestations.
Mice love an easy meal, so leaving a biscuit around where you suspect they’re feeding will give you hard evidence that you have a mice infestation. Simply leave it overnight and check if it’s been gnawed in the morning.
This will also reveal whether you have mice or rats. While mice will gnaw for a bit then scurry away, while smarter, stronger rats will take the entire biscuit so they can store it away to eat later or share with their family.