The topic of rats and their uninvited entry into our homes has recently come up on the Facebook Group for my neighborhood.   Someone recently sent me a private message asking for more details.   Since more than one person may find this interesting I opted to write a post as well.    I’ll start by saying I am not an expert.   I’m just sharing what I’ve been told , read online , and what worked for me.

Let’s start with why rats are in your home.

For most people it has nothing to do with how clean you keep your home or yard.   In Charleston rats will mostly stay outdoors where the warm weather is not an issue and the marshes provide plenty of uncontested food and water.   When it gets cold enough, close to freezing, they often look for easy places to nest.  That is almost always an attic or garage at a home near a marsh.

Blocking Access

The most effective means of keeping rats out of your home is making it far harder to get into your home than alternatives.   The ultimate alternative is having them choose to nest in the woods where it is dry and they have plenty of nesting materials.   A typical-size adult rat can get into any opening they can fit their head into, not including the fur.   That usually means an opening the size of a quarter!    Your first goal is to block off any access to the home.

Block Vinyl – Bottom Edge

In Charleston , where vinyl siding is prevalent, you’ll want to start by ensuring your vinyl siding is properly attached around the entire perimeter of your home.  A common access point is a loose piece of siding around the bottom edges.  Run your hand around the entire bottom edge of your siding (wearing gloves of course to prevent cuts from pulled-out nails).  If the siding is loose and you can fit your thumb between it and the outside of the home the rats will get in.

Yes, they can fit between vinyl siding and your home and will use it as a simple path to your soffit (the part around your roof that sticks out).  Almost all soffits on vinyl homes are thin plastic the rats either chew through or push up to get into your attic.

The fix?   Re-nail the edge straps that hold the siding in place.   Don’t be surprised if you find that strap is coming out because of wood rot. That sucks.   If you’re living in Charleston it is common due to high humidity and living near salt water.

Block Soffits

You’re not done there.  Rats are also great climbers.   That means they will get on  your roof , hang over an edge, and again look to enter through that eve.   Make sure all soffits cannot be easily pushed up. Many on my home need to be re-secured.   Some needed to be fixed from inside the attic.    The most commonly-used entry points had to be modified by putting thin wire between the joists behind the soffit to prevent rats from pushing it up or eating away the plastic.

The fix? Many soffits are not installed properly.  The ends should snap together securely making it very difficult to push up.   In some places, typically near the corners of the home the soffit is not secured properly with an end cap or nailed to a joist.   In those areas we used heavy-guage chicken wire nailed between the joists.

Block End Caps

Most vinyl homes have end caps with large gaps behind them.  You can feel a 2″+ opening behind those end caps on most homes.    The rats easily run up that to the corner of your home were carpenters often take short cuts or miscut the siding and find a way in.   Block the bottom and tops of those end caps.

The fix?  Use steel wool, we found fine grade works great, and spray foam.    Make sure it is expanding foam rated for use around doors and windows so it is flexible and won’t crack your siding and can stand temperature and moisture issues outdoors.   Rats will eat through foam but once they get to the steel wool they stop; it is no better for their digestion than ours.

Non-Vinyl Homes

If you don’t have vinyl homes there are similar entry points on homes with wood or cement-board siding.   The same techniques apply though the issues with bottom-edge entry almost always mean an area rats have chewed through or that have wood rot.   If you have a crawl space be sure to check there as well.    Rats love to get up around any entries near pipes.    The same foam and steel wool trick for end caps works great here.  Don’t use foam on its own.

The fix?  Repairs.   Keep the exterior of the home maintained and make sure any rot or parts critters have eaten through are removed and replaced.

Finding Current Entry Points

Rats leave markers where they enter homes.   The oil and dirt on their skin and fur is rubbed off at the point they are entering your home.  Look for dirty marks that look similar to used Chapstick in odd places around the home.   This is a very good indicator of where they are getting in.   The places I found around my home gave me a whole new respect for how crafty rats are.   This is how I found the entry at the end caps as well as a soffit entry that I still cannot figure out how they hell they got in there – about 6 foot away from the edge of a home and a good 16″ overhang with no loose siding in the area.

Make sure you go inside your attic or garage and look from the “inside out” as well.   Look for the same “grease trails” near the edges of your home. LOOK UP.   They will also come in through loose ridge vents (top edge where the roof meets), soffit vents, dryer vents, plumbing vents where rubber boots make a good meal while making a new entrance.

Blocking The Scent

Rats have a great sense of smell.  It is their primary means of finding their way into and back into your home.    Their primary means of navigation is to follow the scent of their trail; which is left my urinating and defacating everywhere along the path.    They also can “smell” the warm air leaking out of your home and/or the scent from their nest.    If the air is escaping from your home (attic, garage included) they’ll follow that trail to the easiest access point.

Make sure you seal off any entry points they are already using.   Then find any other places where you can see gaps to the outside.   On a colder day feel around the attic for places cold air is coming in that is not a vent.   If your vents are soft plastic (soffit vent, ridge vent, eve vent, etc.) you may need to use the chicken-wire trick to keep the rodents out; luckily mine were uncompromised so I just check them every year for issues.

Make Your Yard “Scary”

Rats hate to be out in the open.   Probably because they are tasty meals for the hawks and other animals in the area.   They WILL find anywhere they can to hide, especially in their travel to and from your home.  They will prefer to go to the local drainage pond or marsh for water and food.   Your goal is to expose that route as much as possible.Do NOT have any excess “stuff” in  your yard if you can help it.  The more potted plants , swing sets, bikes, garbage cans, and other things they can hide under/behind/around the better.They love fences.  They make a perfect “highway” that hides them from at least one direction and is very easy to run along.   If you are out in your yard in the evening stay quiet and wait.  You’ll see not only squirrels but rats using that fence as their personal jogging path.

Trim up shrubs.   Try to keep them off the ground.    If the branches are down to the ground the rats will hide in there whenever they need cover during their hunt for food and water.

Unfortunately I really like my fend and landscaping.   I’m not letting the rats “win” to the point of taking down my fence and pulling out shrubs.    Instead I check my home twice a year for entry points.    I have, however, cleaned up a lot of things around the yard and tend to trim back most of my landscaping more than I used to.   It does cut down on “paw traffic” somewhat.

Speaking of landscaping, rats can jump.  If you have trees near your home they will jump on your roof to find access.   Keeping trees at least 6 feet from your roof is a good idea (which I need to follow myself).

Killing The Critters

If you block off the access there will be a good chance some rats will be trapped in your home.    There is also a great chance that your first go-around will not find all the places they can get in.  The rats are far better at this than you are.   They do this for a living.  Hopefully you do not.   This means you are going to need to get them out of your home.I tried a LOT of different methods.   The number one most effective method by  a mile is a spring trap.  You know, that old fashioned kind.     The more effective model is the newer plastic models that are far easier to set without breaking a finger and easier to dispose of your “catch”.

There are some caveats with the plastic models.   NEVER use any type of oil-containing product in the trap.  The most common is peanut butter.  The oil breaks down the oils in the plastic and the trap will fail.   Use rat bait.  It works well.

One advantage of wooden spring traps , if you are careful enough to set it properly, is that you CAN use peanut butter.   In my experience peanut butter is the best bait by far.    However I did end up trading for plastic traps and the bait made for them after a half-dozen times either thanking God I didn’t lose a finger or cursing as I tried to get squashed rodent out of the trap.

In either case use a MINIMAL amount of bait.   Rats are crafty and will often use your bait as food without setting off the trap. I cannot tell you how many times I found empty traps with no bait.   When I checked the trap… well, let’s just say that is how I almost broke a few fingers by using too short a “stick” to do the test.

Poison

This is great for control companies because it is something you have to maintain.   That means a monthly contract to keep feeding the rats.   Rats build up a tolerance VERY quickly.  As such most poisons on the market these days are completely ineffective.   They are great a killing fish, birds, and pets however.    If you are in Charleston you live near a marsh.

My recommendation, do NOT DO IT.    Especially the outdoor traps.      There are FAR more rats than you’ll ever catch or kill out in those marshes so you are just throwing your money away.

On a related note, setting outdoor traps is useless.   You are literally giving the rats a reason to COME to your home.  You are feeding them.   With a proper trap you are only killing the first rat.  The others get a free meal.

Summary

The most effective method of dealing with rats is to secure the perimeter of your home.

Use spring traps with bait and kill the rats that are already in your home.

Do NOT use poisons.

Do NOT set outdoor traps.