Indicators of bedbug infestation include waking up with red, itchy welts, finding blood stains on sheets and pillowcases, and seeing dark or rusty spots on the mattress, sheets or surrounding walls, notes WebMD. Finding bedbugs' shed skins, egg shells or fecal spots on the mattress can also indicate an infestation.
If infestation is suspected, carefully inspecting the mattress, box spring and bedding for bedbugs and their excrement, recommends WebMD. Items around the bed should also be examined, including books, telephones, radios and electrical outlets. Bedbugs may also reside on carpeting and clothing. They generally enter homes on used beds and furniture.