sitting on your dining room wall, you might have no way to find out that it is a House Centipede (known aliases Scutigerida Scutigeridiae and "big scary bug with lots of legs) and furthermore that said bugs are supposedly beneficial because they eat other less agreeable bugs like spiders, termites, cockroaches and silverfish. Which is not to say I'm happy to see such a creature on my wall. But thanks to modern technology I at least know what this two-inch bundle of legs and feelers is actually up to.
(Note that I snagged the above photo from the Wikipedia article. I tried to take my own, but while I was focusing the resident feline batted the bug off the wall and proceeded to chase it around the kitchen. It was last seen heading for sanctuary under the stove.)