There are several signs that can indicate you have bed bugs. The first is actually seeing the little pests skittering through your house. They tend to feed at night (generally where their hosts — people or sometimes animals — are sleeping), but can come out in the day if they’re hungry enough. Adult bed bugs are rusty red in color, as thin as a credit card and the size of an apple seed. Sometimes they can be mistaken for carpet beetles or small cockroaches, so if you’re confused you can use this helpful guide by the EPA for identification. Although they are harder to see, spotting the eggs themselves is a surefire sign. Another common symptom of having bed bugs is finding the exoskeletons of the nymphs near your bedding and other bed bug-friendly locations. The more exoskeletons you find, the larger the infestation likely is, because as they mate and proliferate more and more juveniles are born and cycle through moltings. Rust-colored spots — which the Centers for Disease Control and Prevention explains are blood-filled fecal dropping that the bugs excrete on bedding and furniture — are another sign that bed bugs are living in your home. In addition, a sweet, musty odor can be an indicator of bed bugs.