What Can Rats Chew Through? Wood, Brick, Plastic & More What Can Rats Chew Through? Wood, Brick, Plastic & More

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What Can Rats Chew Through?

By: Rita Stadler

Have you ever seen an “eye-boggling” rat?

The muscles controlling a rat’s jaws are very powerful, and anchored around the eye sockets, running behind the eyeballs. When a rat grinds his teeth, his eyeballs can vibrate in and out; this usually indicates pleasure and contentment.

Rat chewing on nuts and seeds

Why Do They Need Such Powerful Jaw Muscles?

Because their incisors never stop growing! Rats have 16 teeth; four incisors in the front (two on top and two on bottom) and 12 molars (six on each side with three on top and three on bottom). Constantly gnawing on things and bruxing (repetitively grinding incisors together) wears their teeth down and helps to keep their incisors sharp. If their teeth were allowed to grow unchecked, they would grow continuously in a spiral at an 86 degree angle, making it impossible for the rat to close its mouth or eat, resulting in death. 

What Do Rats Chew On to Wear Their Teeth Down?

These pests will chew on anything that is not harder than their teeth. The Mohs Scale, developed by German mineralogist Friedrich Moh in 1812, measures the hardness of gemstones and minerals based on their ability to scratch another gemstone or mineral.  The scale ranks from 1 (softest, such as Talc) to 10 (hardest, such as Diamonds). Rat teeth rank about 5.5 on the Mohs Scale, harder than iron or copper. Human tooth enamel only ranks about 5 on the Mohs Scale. Because their teeth are so hard, rats are able to chew through most of the materials people use to keep them out, such as:

  • Plastic
  • Wood
  • Brick
  • Cement
  • Lead
  • Asbestos
  • Aluminum
  • Cinder blocks


Hard materials such as bricks, cinder blocks, and soft forms of concrete aren’t a problem for these critters. They can even get through softer metals like aluminum sheeting, lead, copper, iron, and gold. That means you shouldn’t try to keep rats out of your home with gold! Since they can chew through softer metals, they can definitely chew through even the hardest of woods. They’ll usually chew through flooring and baseboards in your home, especially where there are already smaller holes such as near pipes. Other materials they can get through include thin glass, plastic (like window & door screens and water pipes), drywall / sheetrock, asbestos, and electrical wires.

Super strong teeth are not the only superpower-like trait these rodents possess. Rats can fall 50 feet without injury; they can swim and tread water for 3 days without drowning; they can squeeze through openings the size of a quarter; they breed at an astonishing rate, rapidly populating any given area; and last but not least, their genes have mutated, making them immune to most rat poisons.


Materials They Can’t Chew Through

Rats have the most powerful jaws of any rodent and even of many other species. Some estimates say their jaw muscles are able to exert up to 6,000 lbs. of force per square inch, which is extremely high. For comparison, a human’s jaw bite force comes in at around 70 lbs. per square inch, a hippo at 1,800 PSI, and a Nile crocodile at 5,000 PSI (see more here).

That’s a strong bite! But there are still some things rats just can’t chew through. These are materials you should keep in mind when you’re trying to keep them out of your home.

  • Solid Concrete – Rats cannot chew solid concrete. Many homes have a solid concrete foundation, so as long as there aren’t any large cracks in the concrete, these pests won’t be able to get through.
  • Stone – These rodents can’t chew through stone. That makes stone flooring and ceramic tile great materials for flooring options. Keep in mind that all ceramic tiles are not created equal. Some tiles might be weak enough for rats to chew through.
  • Hard Metals – Since rats can’t chew through hard metals like steel, it’s one of the reasons it’s recommended that holes are filled with wire mesh and steel wool and then filled with caulking. Metal tiling is also a great way to prevent them from getting into your home from the floor. Metal tiles come in many designs too, even hardwood.

How to Keep Rats Away

These critters may seem like an invincible opponent, but it is possible for homeowners to keep rats out. The first and most important step in preventing an infestation is good sanitation.  Removing food and water sources will go a long way when getting rid of rats. Store pet food and pantry goods in glass or metal containers and use a covered trash can. Keep things picked up and organized so there are fewer hiding places for rodents. Outside of the home, keep shrubbery and wood or compost piles away from the building.

The second step is to block off entry points and make the exterior of your home rodent-proof.  Even though they can chew their way through many building materials, you don’t need to leave the door open for them. Use metal screens over chimneys and dryer vents. Make sure the building’s foundation and roof soffits are well maintained.  Keep window screens in good repair and install door sweeps if there is a gap under any exterior doors. If you see rat feces, see if you can trace the droppings back to where they might be entering the building.

Lastly, protect property with a plant-based rodent repellent. These pests have poor eyesight, but an exceptional sense of smell. As a matter of fact, rats have been trained to sniff out landmines, drugs, and even to serve as rescue rats sniffing out survivors after disasters. Fresh Cab® Botanical Rodent Repellent uses essential oils that smell pleasant to humans but are offensive to rodents. The odor deters these creatures and prevents them from returning. Placing Fresh Cab pouches around your home and storage spaces will protect the areas against rats and mice.


  • Will Harris

    Rats don’t have a strong bite because their teeth constantly grow. Ever-growing teeth evolved as a result of their chewing behavior not the other way around. Strong bites are useful for cracking open nuts and other seeds which many rodents eat. Their also help in burrowing and making homes in wood.

    1. Rita Stadler

      Hi Will,

      Thanks for sharing that extra information about rats, they sure are neat!

  • kensey

    lmao i keep rats as pets

    1. Rita Stadler

      Hi Kensey!
      Some rats make great pets! We’d love to hear more about yours 🙂
      Thanks for reading!

  • Joe Goodman

    I had a task of closing a pipe from rats getting into it from outside. Iron meshes didn’t work. If the mesh is too thick, I can’t bend it around the pipe (or fit it snugly inside the pipe). If it is thin, they chew through it in 2 weeks. Also, the mesh has to be cosely knit (no more than quarter inch gaps). Eventually no mesh worked.

    I took a cylindrical steel container that my friend had gifted me as a spoons/forks holder (which had 1/4th inch holes in it) and fitted it snugly to the pipe using a rubber tubing. Now, that has stood the test for 2 months so far! But, I have to clean up the garbage inside it manually once every 2 weeks (because, the holes are too small). I am happy with the solution.

    1. Rita Stadler

      Hi Joe,
      Rats can be very persistent and almost ingenious when it comes to getting inside. I’m glad you were able to find a solution that works for you!
      Thanks for reading!

  • Annette Grassman

    I am having a problem with alot of rats. They were in the doghouse last year. We killed over 50 rats. They were under the floor. Now they are back. They have burrowed under my pool. My pool us made of the strongest material. I have noticed the water level going down. Do you think rats could chew through the bottom of the pool? I have a Splash Pool which has no liner.

    1. Rita Stadler

      Hi Annette,
      So sorry to hear about your rodent situation! It’s hard to say if rats may have chewed through the bottom of the pool without being able to see if any damage done to pool. It sounds like Fresh Cab Rodent Repellent would definitely help prevent recurring infestations in your doghouse though. All of our products are pet-friendly and free from harmful chemicals. The repellent may work around the pool as well, but the effectiveness will diminish if the pouches get wet or are exposed to a lot of air flow such as when they are placed outdoors. Fresh Cab works best when used in enclosed areas.
      Thanks for commenting!

  • Pam

    This blog is very helpful, thank you for having it! I just noticed today I heard a rat (assuming one) scurrying around in the ceiling. How fast can the rat chew through my ceiling and what’s the best way to get rid of it without harming myself or my cats? There is a very small crawl space door at the opposite end of the house which is not easily accessible.
    Thank you for any and all suggestions.

    1. Rita Stadler

      Hi Pam,
      Thanks for stopping by! It’s hard to say how fast a rat could chew through something, but our Fresh Cab Rodent Repellent is definitely a safe solution to get rid of rats without harming your or your pets. Check out this video for some helpful usage tips:

      Thanks for commenting!

  • Ed R.

    Is there any mesh stainless steal products I can purchase to cover items like tents, sleeping bags, camping equipment, etc., to prevent rats from gnawing through it?

    1. Rita Stadler

      Unfortunately we don’t know of any specific products for what you’re describing, but you’ve got the right idea! Try checking your local Ace Hardware, they probably have some different options and the know-how to get it done.
      Thanks for commenting!

  • Rose

    I have something under my jacuzzi tub in house sounds like chewing I hear it move.
    How can I get rid of it?

    1. Rita Stadler

      It’s hard to know how to get rid of something if you don’t know what it is first. Look for signs of gnaw or chew marks, as well as any droppings or other clues about what is under your jacuzzi. You may need to call wildlife removal or a pest control professional. Once the intruder has been removed, use Fresh Cab Rodent Repellent pouches in the surrounding enclosed area to prevent pests from returning. Make sure any potential entry points are sealed shut so nothing gets back inside. Thanks for reading!

  • shirley gosche

    will mice and rats chew plastic trash bags?

    1. Rita Stadler

      Hi Shirley,
      Yes, mice and rats can easily chew through plastic trash bags. Keeping trash in a covered can with a tight fitting lid will help prevent this problem. Thanks for reading!

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