Bed bugs usually leave behind rusty or reddish stains on bed sheets and mattresses, caused by the insects being crushed. If you see dark spots that look like dried blood (about this size: •), these are excrement left behind by bedbugs, and may even bleed onto the fabric. Bed bug eggs are tiny (about 1mm) and pale yellow, while empty eggshells are simply the skins shed by nymphs as they grow larger. Of course, live bed bugs are another tell-tale sign of an infestation.
The # symbol isn’t officially called hashtag or pound.
Its technical name is octothorpe. The “octo” means “eight” and refers to its points, though reports disagree on where “Thorpe” came from. Some claim it was named after Olympian Jim Thorpe, while others argue it was just a nonsense suffix.