Here are some ways to check for an active bed bug infestation in a room before moving in: Inspect the bed: Look for small, reddish-brown insects or tiny, rust-coloured stains on the sheets, mattress, and box spring. Check for bites: Look for bite marks on your skin after sleeping in the room. Bed bug bites can be itchy and appear in a line or cluster. Use a flashlight: Search for bed bugs in cracks and crevices around the bed, in the seams of the mattress, and in the headboard. Ask the landlord: If you're unsure, ask the landlord or property manager if they have recently treated the apartment for bed bugs or if there have been any reports of bed bug infestations in the building. Hire a professional inspector: Consider hiring a professional pest control inspector to check for bed bugs before moving in. They have the training and equipment to thoroughly inspect the room and identify an infestation.