Many people never see a live bed bug until an infestation is well established. Droppings, though, show up early and stay put, which makes them one of the most reliable signs you can find yourself. The NHS lists small spots of bed bug poo on bedding and furniture among the main signs to look for.
What the droppings are
Bed bugs feed only on blood. What they excrete is the dried remains of that blood meal, which is why the spots are so dark and why they behave like a liquid stain rather than a crumb. They are not solid pellets like mouse droppings.
What they look like
- Colour: black or very dark brown. Fresh spots can look slightly reddish.
- Size: tiny, roughly the size of a full stop on a printed page, or the tip of a ballpoint pen.
- Pattern: usually in clusters, sometimes dozens together, where the bugs shelter. Scattered single dots on their own are less telling.
- Texture: flat or very slightly raised. On fabric they soak in and can leave a faint halo. On hard surfaces such as wood, they sit on top like a drop of dried ink.
Where to look
Droppings collect where bed bugs rest between meals, which is usually within a couple of metres of the bed. Take a bright torch and check:
- The mattress piping and seams, all the way round, top and bottom.
- Labels and tags, which create a fold that bed bugs like.
- The divan base, including under the fabric on the bottom and round the corners and castors.
- Bed frame joints, slats and screw holes, especially on wooden frames.
- The headboard, particularly the back and where it fixes to the wall or frame.
- The bedside table, inside the drawers and at the joints.
- Skirting boards, plug sockets, curtain tops and picture frames near the bed, in a heavier infestation.
- The sofa, if someone sleeps on it or sits there for long periods in the evening.
Do not strip the bed and wash everything before an inspection if you can help it: a technician wants to see the evidence where it is.
The damp-cloth test
This is the simplest check you can do. Moisten a cotton bud, a cotton pad or a corner of a white cloth with a little water and wipe one of the spots.
- Bed bug droppings dissolve and smear into a reddish-brown streak, like a felt-tip pen mark.
- Mould spots usually wipe off as a grey or green smudge and come back in damp areas.
- Dirt or dust tends to brush off dry and does not stain.
- Ink or paint generally stays put.
The test is a good clue, not proof. If you find clusters that smear, alongside other signs, it is time to get a professional opinion.
Droppings or blood spots?
Small rusty or red marks on sheets and pillowcases are also common with bed bugs. These are usually a bed bug crushed while feeding, or a bite that has bled a little. They are larger and redder than droppings and tend to be on the sheets rather than in the seams. On their own they can have other causes, such as a nosebleed or scratched skin, so they count as moderate evidence.
What else to look for alongside droppings
Droppings are much more convincing when you find them with:
- pale, empty shed skins, which young bed bugs leave behind each time they grow;
- eggs, which are about 1 mm long, pearly white and glued into cracks in small groups;
- a live bug, which you should keep in a sealed bag or jar to show someone.
If what you find does not quite match, our guide to bugs that look like bed bugs covers carpet beetles, booklice and the other insects that cause confusion.
Cleaning droppings off
Once a technician has seen them, droppings can be cleaned off hard surfaces with a damp cloth and ordinary detergent. On fabric they can stain. Washing at a high temperature helps, and the NHS suggests washing affected bedding and clothes on a hot wash and drying them on a hot tumble dryer setting for at least 30 minutes. Cleaning removes the evidence but not the bugs, so do it after the inspection, not instead of one.
What to do if you find them
- Photograph the spots in good light with a coin for scale.
- Leave the bed where it is and keep sleeping in it, so the bugs do not move to another room.
- Avoid shop sprays and foggers, which can spread them.
- Arrange an inspection. A technician will check the bed and the rooms around it and tell you how far it has spread. See bed bug inspection in Leeds and typical prices in our Leeds cost builder.
Found spots that smear? Use the form below and we will put you in touch with a Leeds technician who can confirm it and give you a fixed price.