Environ Pest Control

How Do You Know If You Have A Mouse Infestation?

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What are the signs of a mouse infestation & how do I know when they are gone?

Before you can get rid of mice, you need to realise they’re in your home or business in the first place.

Mice are elusive, cautious creatures, but if you know what you’re looking for you can spot them and take action before your mice infestation becomes too severe. Mice spread disease as they scurry out of their dirty hideaways and onto your surfaces, so don’t wait around if you suspect you have an infestation.

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Sights, Sounds and Smells of a Mice Infestation

Seeing mice

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.

Hearing mice

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.

Smelling mice

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

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.

Mouse holes

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.

Mouse markings

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.

DIY Techniques for Confirming Mice Infestation

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.

Flour test

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.

Biscuit test

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.

Signs of a mouse infestation

  1. “If it’s rice, it’s mice”, mouse droppings are the size of a grain of rice.
  2. Look for gnawed holes, size of a ballpoint pen or bigger.
  3. Mice leave smearing, greasy marks along skirting boards and around holes.
  4. Squeaking and scraping sounds that stop when you make a noise.
  5. Scatter flour on surfaces overnight so you can see their footprints.
  6. Leave a biscuit out: if it’s gnawed, it’s mice; if it’s gone, it’s rats.

Still Not Sure If You Have a Mice Infestation? Call Environ Now

If you want a complete, thorough diagnosis of your mice infestation which will identify how they got into your home, where they’re nesting and what they’re feeding on, call Environ now or

click here

to get in touch with our BPCA-certified pest control team.

Here are some other helpful articles about Mice

Do Mouse Traps and Poisons Work?

Do mice keep coming back, no matter how many traps you put down? Find out why DIY mouse control rarely does the job and how to finally get rid of mice, for good

How to Get Rid of Mice in the Kitchen

Your kitchen is the most common part of the home to find a mouse infestation. Luckily, good habits and hygiene is often enough to prevent mice in your kitchen.

Can Mice Just Disappear Without Me Doing Anything?

Are you hoping that the mice in your home will leave by themselves? They won’t, and if you don’t do anything to stop them, the infestation will get much worse.

What Is The Difference Between Mice And Rats?

Worried you have rats or mice? Learn how to tell the difference with our guide, from their behaviour to the holes they make and the droppings they leave behind.

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