Hmmm...the slums of Highland Park. Over 80% of my work is in the towns
of Highland Park and University Park (5 miles north of downtown
Dallas)where both towns break the top 20 list for most wealthiest cities
in the US. Roof rats and outdoor roaches are dealt with on a daily basis
for me out there. Not so much sanitation issues, but the manicured
landscapes in these 60 plus year old neighborhoods are the perfect
environment for them.
Same in Florida. 12 mos. growing season guarantees palm berries and
citrus are available. Neatest thing about roof rats was seeing one run
to the bottom end of a downspout and hear the critter climb up the
inside. I had heard noises by the downspout before, but thought that
must be the "down" elevator and trees the "up" elevator :o)
Wee bit overboard there. In some areas, mice are endemic. Folks learn to
deal with them without removing the cat (who's mere presence reduces the
number trying to get in and this one is a mouser so even better than that).
Daniel, set a few traps where the cat cant get at them, with peanut butter.
Also, an odd but very useful one for the smaller levcel problem
(non-breadbasket wheatlands of USA) is a plastic owl on a string so it
swings in the breeze, strategically placed <g>. Excellent interior devices
you plug into the wall that emit a high pitched sound and irritate the
$E@#$#@ out of mice. Careful, they have to be pitched to not also drive the
cat insane <g>.
Yes, do seal all holes you can find outside. Once you do that, interior
ones arent but a cosmetic issue. You can seal them fast with just a fine
mesh metal screen. They will eat through plastic ones but not metal ones.
Likely entry points? Attached garage and a door to the kitchen or other
part of house with an 1/2 inch 'gap' covered by mere plastic 'bottom skirt'.
Mice can move that out of the way and get through fine.
True, I took it as a mis-name though since the cat won (grin).
Lots of people who've never seen a real rat, think mice are the same. I got
the heebeejeebee's scared outa me in Vladivostok Russia at night once by the
real thing. I swear that sucker was over a foot long not counting the tail!
There's this underground walkway you go through to get to the main part of
town from the ship piers and that was where I saw it.
There are a couple of basic species of rats and probably hundreds of
sub species. The roof rat that we see most in Florida is smaller than
a small squirrel without the bushy tail. The roof rat has a tail
longer than the body. I doubt there is really much difference in any
practical sense. A squirrel is just a rat with a publicist. You don't
want either of them living in your house. They are really "outside"
animals that stray inside looking for a home.
The nasty rats are the European "Norway" rats. They are the ones that
get bigger than a cat and tend to live more where the people are. That
is your typical city rat. The problem with all rats is how fast they
can make baby rats, usually only limited by the food supply. They can
eat damn near anything so that is tough to control. Most ornamental
trees and shrubs produce a seed or fruit they will eat. Of course a
trash can is a rat buffet. The raccoons and dogs open the can and
scatter the trash around, the rats come and clean up the scraps.
Cool! I was reading the other's ntes on the roof rats. I'm not familiar
with them so it was interesting, especially the post on the one running up
Snicker, we got lots of squirrels here. Any openings to the attic here have
to be braced inside with heavy metal screeing to keep them out.
Thats what I've seen. On ships, we have rat guards on the lines to keep
them from running up. Once a ship gets an infestation, it's horridly hard
to get rid of them. Roaches too are really hard.
Sounds like you might be an exterminator so know more than most of us would
Lars is our exterminator. I just took a lot of time to study my enemy.
The more you know about pests, the easier it is to control them.
You will never eliminate rats, the trick is just to reduce the number
and keep them outside.
NEVER kill a snake! They eat more rats in your yard than a cat and
they don't dig up your flower beds..
BTW I think boric acid is probably the best roach preventer. If they
would liberally dust the floor under cabinets in the kitchen before
they set them I think your bug problem would be vastly reduced. The
same for the stud cavities. Boric acid is not really that toxic to
people but you should still keep it sequestered.
Well that would be a yes and no answer with that. If boric acid would
be properly applied it can be a good product, but if it is heavily
applied it is just a repellent causing insects to bypass where the BA is
placed and just show up in places where the dust in not. If it is being
used in cabinets because the thought of it being safer than the store
bought insecticides BA dust/powder will be 30 to 150 times more toxic
than any of the insecticides sold for home use or put out by an
exterminator along with no unsightly dust to see.
There is a difference in of toxicity of BA dust sprinkled about for
insect control that is at 97%-100% strength and products that just
contain a small percentage of BA in there mixtures. When used in eye
washes it is at a very low concentration...check the label of a lot of
commercial eye washes and you will even see Hydrochloric Acid on the
label. :) You might be thinking of Diatamaceous Earth that is fed to
cattle to help with worms that is also put out for insects as is BA. It
was used a lot at the turn of the 20th century as an antiseptic wash for
surgery but was stopped. http://tinyurl.com/yqr68y
A book from 1899 to prove what? Show me something that proves BA is
30-150 times more toxic than ANY pesticide? Perhaps if I sit down and
eat spoonfuls straight from the container. I agree with your point
about dusting to keep roaches away....They can find the house even if
you build mounds with BA, and they can always follow you home from the
grocery store :o)
the reference to that old book was not to prove anything but to just
point out at one time it was used internally, but I think that practice
is long gone.
we'll try this way and any insecticide can be broke down this way...
easy enough to find the LD50 of different chemicals on the web, the
lower the number the more toxic the substance. I'll use cypermethrin
because I know where to find an example of the ld50 of finished product.
Cypermethrin is one of the older pyrethroids used in pest control, the
newer generation pyrethroids are even more "non insect" friendly at use
rates. The ld50 of BA is around 2700mg/kg which is mild and cypermethrin
is 250mg/kg which means cypermethrin molecule is over 10 times more
toxic than the BA molecule...bad. But cypermethrin is not the
insecticide, it is just an active ingredient in the insecticide which I
use it at from .1% down to .025%. If you go to the makers site for the
Consumers Product Information, http://tinyurl.com/yreu2r ,it shows the
cypermethrin product at .6% rate has a ld50 of greater than 20,000mg/kg
(over 7 times less toxic than BA) but .6% is 6 times stronger than what
the label allows to be used on a maintenance program, such is the bug
man coming in every three months to help keep the insects away. So if
that is the case .1% would have a ld50 greater than 120,000mg/kg which
would be over 43 times less toxic than boric acid.
But wait...once the water evaporates you now have that highly toxic
cypermethrin hanging around....in this case remember all numbers are
approximates..every substance has different actual weights when compared
to another and there is converting ml to mg to deal with also....
Using the lower rate found on boric acid dust labels (97% strength), if
an ounce contains 28350 mgs (rounded up) then an ounce (2 table spoons)
of boric acid at 97% has 27499.5 mgs of BA which has a 50% chance of
killing 9.9 pound animal. ...amount of mg of BA in an ounce divided by
the ld50 of BA (2770)
an ounce of .1% cypermethrin insecticide would contain approx 28.35 mg
of cypermethrin in it, which means it would take 8.8 tablespoons to
reach it's ld50 of 250. But the ounce of boric is 9.9 times above it's
ld50 for just one tablespoon. It would take 87.12 ounces (almost three
quarts) of the cypermethrin product to achieve the amount to have a 50%
chance of killing a 9.9 lb animal, compared to one ounce for BA. The
average amount of insecticide used in a home on a quarterly basis around
plumbing, corners, windows etc might be 20-25 ounces.
BA is cheap and easy to use and can be effective, but it is not the
Just to put this all in perspective, the LD50 of table salt is
somewhere around 4000mg/kg, so while these insecticides are more
toxic than table salt, they really aren't all that toxic to mammals.
I wouldn't put it in the cabinets, just "dust" it under the cabinet
before you set them. The bugs tend to go where you can't see them
diring the day and that is where I would treat them. If you are
"infected" you need more extensive treatments, even calling in a pro.
The trick is to keep down the stragglers before you get an established
The nasty roaches are the little ones anyway. (asian and german). The
big scary looking "american" cockroach we get in Florida is really
fairly easy to kill.
They are "palmetto bugs" in the same sense a roof rat is a "palmetto
squirrel". They both live in the trees outside and stray into your
house if you let them.
Don't know the ability of rats, but mice can squeeze through 1/4"
opening. My son trapped a bat in his house a while back. It landed on
the window side of a sheer curtain, and he smacked something flat
against the curtain to trap it. Thought it should be dead, smashed
flat, but only injured. Got a box to take him outside and finish the job.
Bad exterminator joke... an adult mouse can get into the opening the
size of a dime...an adult rat, an opening the size of a quarter. So
what's the difference between a mouse and a rat? 15 cents....
I wouldn't block the hole right away, I would put a glue trap in front
of it. Mane sure you lond it down well. I usually staple it yo a piece
of plywood or tywrap it to a 1/8" steel plate that is too heavy for a
rat to run off with. If your cat caught one you have more.
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