Tuesday, June 19, 2007

Bug Proofing

Back when our first cockroach of the year showed up, my husband said he wondered how it got inside. Since I've read roaches can squeeze in through very small spaces and live in tiny places, I never thought much about it but the truth is that there aren't any gaps in the floor boards, ceiling, or holes in the walls through which insects could pass if they were living in such places. All of our windows and sliding doors have screens so, unless the roaches are strong enough to slide one open and shut or small enough to squeeze through the most infinitesimal gap between screen and frame, there was no way I could think of that they could get in.

While considering when to take down and clean the kitchen exhaust fan, it suddenly occurred to me that it represented a prime orifice through which any sort of small creature or insect could enter the apartment. In fact, at some point a long time ago, a small lizard actually was crawling on the wall in our kitchen and that was a serious mystery until now. The fan has no screen of any sort behind it but rather a hood which is open to the outside. Anything that is 6 inches or smaller can easily crawl or fly up into the vent and enter through the fan blades when the fan is off.

Since the fan opens into the kitchen and is designed to suck out natural gas fumes as well as cooking odors, anything which is attracted to the smell of food will be drawn to the vent. You can't see behind the fan in the picture above but the hood leading to the outside is absolutely coated with thick, greasy crud resembling cakes of soot. It can't be cleaned by me, of course, as it's an external vent which is very high up on the wall outside and has 20 years of gunk on it. I imagine there is something in there to attract the discerning roach should he find his way up there (the males can fly). I also wonder now if mosquitoes and moths may have been getting in this way.

Since this is the biggest opening which is unscreened that leads outside, I decided it'd be a good idea to do something to screen it off in some fashion so I picked up a sheet of batting designed to filter oven exhaust fans and attached it to the fan's frame. I attached the sheet to the fan pulling it as tightly as possible but the fan is nearly flush with the frame and when it was turned on and started sucking air out, the blade caught on the batting and tore it up.

My husband suggested that it'd work if we found a way to raise the filter higher off the frame and while buying another sheet of batting, I noticed the type of extra long sponges (they're about 1 foot long and about 5 inches wide) that you cut to size. I figured that I could buy one of these, cut it up and use it to raise the filter from the frame.

If you look at the picture above, you can see where I attached the sponge pieces to the frame with double-sided tape (the sponges are white but can still be distinguished from the fan's frame). I then stretched the filter as tight as I could over the frame and taped it down on all sides. Since the filter material is flexible, it still gets sucked inward to a small extent but it's still far enough from the blades not to get hacked up.

The filter should keep the fan from getting filthy with dust but more than that I'm hoping that it keeps anything that is outside from crawling in. It'll be interesting to see if we see no more cockroaches this year after putting on this filter or if they're finding their way in via some other route.


Steve said...

Ah the mighty J-roach, my they are bigger than one thinks. I had no contact with roaches previous to Japan, well other than the time I went to NYC. My place in Japan had a few each summer the size of a piece of a small moose. And fast, sports teams ought to use them as mascots. A quick dash for a shoe, while my wife watched the twitchy thing. Bam! Heel to body, a mess to clean. I read the scent of the kill actually will draw more roaches so out comes the bleach. What a game. They come up the drains as well, I saw a head peak out one morning. Keep ALL food in the fridge. I bought tons of roach traps, did they work....who knows. I sprayed weekly under the kitchen sink, window areas, etc. The tiny red ants were more of a worry, they bite...a pin prick of heat. Devils them. Sitting on the sofa, sockless, in the heat of another monsoon, the ants were active on the tatami mat below. Had to spray weekly as well. One time I had a spider the size of my hand, we call them Wolf spiders on the west coast of Canada. Real fast, only a blast from the insect spray can slow them down. Man the bad karma I had to fight in taking out these insects. Still looking to restore the balance to this day.

Keep you eyes peeled, those flashes of movement you sometimes see are in fact a darting roach. The hunt is on.....

Cheers, Steve


Shari said...

Thanks for the wonderfully entertaining comment, Steve.

We're fortunate that our drain is blocked off so they can't come up through it. It's capped off in the center and has a food catcher with tiny holes so I think we're safe on that account. The only food I leave out is bananas.

I'd read that you shouldn't squash roaches for various reasons. One of them was that females that are smashed just spread their eggs, but it's all just too yucky to me.

It sounds like you have a lot more insect issues than we do. I'm wondering if you live in the countryside given the ants and the alarmingly huge size of your spiders.

tornados28 said...

If that ends up not working, you might try a piece of screen like is used on screen doors.