> the cockroaches and rats won't just materialize out of thin air
In practice, you can assume they do - it's a simplified but accurate model of reality when you're not researching the life of insects and rodents.
Yes, life does not appear "out of thin air", but it constantly tries to get in, will exploit any crack in your defenses or attention to chase after anything that looks or smells like food or safety. It's simpler to just assume annoying critters materialize out of thin air if you leave the right conditions, and ensure those conditions are never present.
It's kind of like thermodynamics / statistical physics: the air around you doesn't really have "pressure" or "temperature", but you may just as well assume they're a thing, since the alternative would be to talk about kinematics of air molecules.
We had a mouse problem once. The ended up being a small hole drilled in the side of the house to install a cat5 cable for a security camera. The hole couldn't have been more than 1.5 cm in diameter, and it had a cat 5 cable running through it - but apparently this was enough space for a mouse to squeeze through.
All you need are some outside cats roaming the spacious yard to discourage the small cute furry little rodents from “cozying” up in your house. When living in an urban dwelling with 50 other families, other strategies are needed.
Yeah; we've had mouse problems in our 90-ish-year-old house ever since we moved in a decade+ ago. Then in the winter of 2019-20, a cat started sheltering in our garage on a regular basis.
We had no mouse problems that winter, and very few since then.
In practice, you can assume they do - it's a simplified but accurate model of reality when you're not researching the life of insects and rodents.
Yes, life does not appear "out of thin air", but it constantly tries to get in, will exploit any crack in your defenses or attention to chase after anything that looks or smells like food or safety. It's simpler to just assume annoying critters materialize out of thin air if you leave the right conditions, and ensure those conditions are never present.
It's kind of like thermodynamics / statistical physics: the air around you doesn't really have "pressure" or "temperature", but you may just as well assume they're a thing, since the alternative would be to talk about kinematics of air molecules.