We recently had our roof replaced and it now has ridge vents which require soffet vents for proper ventilation. I am installing soffet vents but my wife is very concerned about the entry of spiders. I am using good quality vents (they are rigid so their edges do not bow between the fasteners) and I am using a generous amount of caulk between the vent and the soffet. Will spiders lay their eggs on the screen and result in a new generation of spiders getting into the attict.
Thank you for your time and response.
Sealing cracks and crevices will no doubt help to keep out unwanted pests. But there are so many ways these unwanted visitors can get in I'm not convinced this is a viable way to do effective pest control. In fact, we in the pest control industry refer to such effort as a type of "mechanical control". In many situations there can be a good amount of mechanical control needed in order to solve a particular problem. But based on the situation described in your message, I'm not sure there is any reason to believe your work will either increase or decrease the amount of spiders on your home.
That being said, we all know spiders are mostly predatory pests. And as such are likely to move on when food is limited. Which is why in our SPIDER CONTROL ARTICLE we explain that treating the home on a regular basis will many times keep both perimeter invading pests away as well as predatory pests. So if you aren't yet doing some outside perimeter pest control, now would be a good time to start.
Basically treating your soffits, foundation and around other points of entry will no doubt cut down the chance of anything hanging around or entering the home. And spraying roof vents, soffit vents, downspouts, around windows and doorways will also help. A good product to use for this work is the DELTAMETHRIN featured in our article. Treatments will last 2-3 months and it works on a wide range of pests.
Alternatively you can go with an organic solution like the NBS INSECT REPELLENT. It won't kill a thing but insects don't like it and tend to avoid where it's been applied. NBS can also be added to paint and stain and if you had asked about what to use prior to doing all the work you listed in your question, I would have told you to add it to your paint and you'd be covered.
Here are direct links to the products and information listed above: