Bed bugs (Cimex lectularius) are small, reddish-brown insects that feed exclusively on the blood of warm-blooded animals — and they prefer humans. Despite the name, they don't live only in beds. They hide in any tight crack within crawling distance of where you sleep, sit, or rest for long periods.
What bed bugs actually look like
An adult bed bug is about the size and shape of an apple seed — flat, oval, and roughly 4–5 mm long. After feeding they swell, lengthen, and turn a deeper red. Nymphs (juveniles) are smaller, translucent, and become visible only after their first meal.
How infestations start
Bed bugs are hitchhikers. They don't fly or jump. Almost every infestation starts with bugs or eggs riding in on luggage, used furniture, backpacks, shared laundry, or clothing from an infested space. Once inside, a single fertilized female can start a population that grows for months before you notice it.
Where they hide
The first hiding places are within about 5 feet of the bed: mattress seams, box-spring corners, headboard joints, nightstand drawers, and baseboard cracks. As populations grow they spread to couches, recliners, picture frames, electrical outlets, and behind loose wallpaper.
Common signs you have bed bugs
Small itchy welts in lines or clusters, rust-colored spots on sheets, dark pepper-like droppings along mattress piping, pale shed skins, and a sweet musty odor in heavy infestations.
What to do first
Don't throw out your mattress and don't bomb the room with a fogger — both make the problem worse and spread bugs into new hiding places. Confirm the issue with a careful inspection, then call a professional. Sleep Tight Pest Control offers free inspections across Chicago and same-day service when you need it.
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