Checking only for live bugs is not enough, as my understanding is that a lot of times they only come out at night to suck blood then disappear again. So you look for feces (clusters of little dark spots that are essentially dried blood) or little streaks of blood stain. But I'm not really sure how to identify them, as I'm not an expert. And I only look under the sheets and between the mattress and box spring. That's probably not enough, but I don't have 15 minutes to do a thorough inspection each time I check into a hotel.