Bathroom / laundry exhaust fans, and even range hoods typically vent their exhaust through vent hoods like this. Though most vents are originally sold with screens in place, they are often flimsily mounted, quick to deteriorate, or only intended to stop rodents (not insects).
Prospecting scorpions will often find easy access to your home though unprotected vents like this, so it’s important to check these areas when you hunt, and make sure you’re hood has an intact screen or flapper valve in place.