Occasional invaders are insects that normally don't infest houses, but under certain circumstancess will come into homes, sometimes in massive numbers. These insects don't cause damage, or get into food, or bite or sting. They are just a nuisance. In most cases, not much can be done about them, short of keeping your vacuum cleaner handy. Below you find a picture of some the more common ones.
Brown Marmorated Stinkbug
Garden centipede (L) and House Centipede (R)