In winter, wasps are using your walls and your attic crawl spaces to hide from the cold. So, if you intend to go up into your attic, or do some renovations in the wall, be aware that this hazard is much more prevalent in winter, and take measures to protect yourself.
How did wasps get into my walls and attic?
Wasps are notorious for overwintering in homes. Your siding is just bark to them. And, if they sense heat leaking out, they will be drawn to burrow their way in through rotted holes, gaps, and cracks.
The good news is, wasps need food and material to grow their nests. So, you don't have to worry about them growing those nests through the winter. Like most insects, they will go into diapause--a low energy state--and most of the wasps will die off from starvation.
The bad news is, if wasps have had a chance to spend the end of summer and most of fall building the nest in your wall or attic, they will have the numbers to make a trip into the attic a very painful experience for you or your kids.
How do I prevent wasp infestation?
You can usually see where wasps are entering your house. Those are the first places you should get sealed up. Make a note of where they're getting in, and let a professional pest company come in and eradicate the nests, so that you don't end up driving the wasps deeper into your walls, by accidently sealing them in.
A professional will also help you in the inspection of your home, and show you areas that need to be sealed. Use a caulking gun to get most spots. If you have rotted wood, and are able to get those areas repaired, that is the way to go. Otherwise, use the caulking gun to fill in the gaps and holes, until you can afford the repairs.
Screens, door sweeps, and weather stripping are also a vital defense against wasps. Inspect for gaps around doors and windows and have them sealed. These are popular entry points for wasps. I've even seen them squeeze past a screen, and wait for the inside window to open, to get inside. If you have sliding doors, close both the screen and the door. Otherwise, wasps can get past when you open the door and slide the screen door closed.
With some simple exclusion practices and help from a professional, keeping wasps out of your house in winter is a piece of cake. If wasps are already in your home, get them removed. They aren't able to go back outside and get food, so they may try to invade your living areas. Proactive prevention is the best way to handle wasps. Always.