Types of Rats in California

A rat is just a rat, right? Actually, this isn’t quite true. There are different types of rats in California. Why does this make a difference? They display different behaviors and can access different parts of a building. It is vital to know which type you are dealing with, as you may think you are protected when, in fact, you are not. Want to know what you could be dealing with? Read on… 

What Kind of Rats Are in California? 

You’ll find two common species of rats in California. These are the Norway rat and the Black rat. Both share broadly similar characteristics and exist in roughly equal numbers. 

You might be surprised to find that, on the whole, there are only two species that represent a significant nuisance in California. If you thought that there were more, you wouldn’t be alone. However, there is a very good reason for this. 

You may have heard of other species, such as ‘Ship rats’, ‘Roof rats’, ‘sewer rats’, and ‘brown rats’, to name but a few. In reality, these types of rats actually fit within the two rat species that we have named above, and they are just colloquial names. 

So, the Norway rat, and the Black rat, here’s what you need to know. 

The Norway Rat 

If you have seen a Norway rat, you will have also seen the common rat, Hanover rat, Brown rat, Wharf rat, and Sewer rat, as these are all common names. 

The thing that sets the Norway rat apart from its darker cousins isn’t so much its color but its size. Norway rats can grow up to almost twice the size of the black rat.  

You’ll tend to find these rats more prevalent at ground level. They are very common in outdoor areas, gardens and outbuildings.  

The Norway rat will have greyish or brown fur with a pale underbelly.  

Another way you can identify a Norway rat is by the size of its tail. This tends to be relatively short, at around 7 inches long. They also have relatively short ears. 

Confusingly, in certain environments, Norway rats can appear dark in color and can appear almost black! 

Speaking of which… 

The Black Rat 

The black rat is seldom completely black. You’ll actually tend to find that they are a very dark brown in color, with a mottled grey running through their fur. 

As we discussed above, the black rat is smaller than the Norway rat. In fact, their light frame allows them to be excellent climbers, which is where they earn the moniker “roof rats” as they can access the upper reaches with ease.  

Other standout features that will easily be identified include larger ears than the Norway rat. You’ll also notice that they have a significantly longer tail too! 

Are Rats Dangerous? 

The short answer is, yes, they are. Rats are a well-known carrier of infectious diseases and parasites. It isn’t only the rats themselves that are the issue. It is well known that fleas from black rats were responsible for bubonic plague in the 17th century! 

Other pathogens and illnesses they carry include: 

  • Weil’s disease. 
  • Viral hemorrhagic fever 
  • Q fever 
  • Rat-bite fever 
  • Cryptosporidiosis 
  • Leptospirosis 
  • Murine Typhus 
  • Salmonella 
  • Eosinophilic meningitis   

Are you getting the picture yet? None of the above are pathogens that you want anywhere near your home.  

Whether it is a Norway rat, or a black rat, an infestation, or an isolated incident, you are going to want them gone

Dealing with Different Types of Rats in California 

There are a few mitigation strategies that you might want to employ to discourage rats from entering your home or property:

Prevent access 

While it may seem obvious and think your house is rat-proof, it may be time to look higher.  


Do you have any foliage, branches, or bushes touching your home? If so, this is an easy access point for rats to enter your property. As we said before, black rats, in particular, are really efficient climbers, and you’d be amazed at the size of the hole they can squeeze through.  

Trim all bushes back to be several feet away from your property, and yes, rats can jump. 

Seal Holes 

On lower levels, it is worth making sure your property is airtight when it comes to rats. Expanding foam may work, but both Norway and brown rats are more than capable of demolishing this with their powerful jaws and sharp teeth. 

Remove Garbage 

Rats will tend to hang out wherever there is a steady food supply. They love nothing more than tucking into a pile of fresh garbage and will happily chew through refuse snacks to get to their lunch. 

Avoid leaving piles of garbage around where possible, and ensure that all household refuse is placed in heavy-duty bags and then placed inside a solid trashcan.  

Remove Pet Food 

While it might be convenient, leaving food down or out for pets all night is a good way to encourage both of the different types of rats you’ll find in California. They don’t mind eating after others, and that consistent food supply is a great encouragement for them to stay permanently. 

The Most Effective Way to Get Rid of Rats in California 

Regardless of the type, you will want them gone, and there is a quick and easy solution. 

Facility pest control is expert in rodent control and removal. Not only can we rid you of your rat problem, but we can also advise on different techniques that will avoid a return. We are so confident in our ability to do this that we offer a 30-day guarantee.  

As you will have seen from our description of the types of rats in California, they are a real nuisance and quite enterprising when it comes to gaining access to your property. If you have seen a rat, why not get in touch and find out how we can help you?