Is this cockroach poo, or something else?

Found specks, a capsule or a papery skin, but no bug? That is common. Cockroaches hide by day and leave their signs by night. The shape, the size and where you found it usually tell you which animal left it. And signs are useful: they show you exactly where to put traps and bait first.

Before you clean anything, take a photo, close and in good light, with a coin next to it for size and the date noted. You may want it later for a pest controller or a landlord.

What cockroach droppings look like

• Like ground pepper or coffee grounds. Tiny dark specks, sometimes smeared into brown marks, clustered on cupboard hinges, shelf edges, the top of door frames and behind the fridge. This is the German cockroach.
• Bigger, blunt at the ends. In basements, under sinks and near drains. These come from the larger American and oriental cockroaches.
• Pepper-like, but high up. On high shelves, behind pictures and around electronics: often the brown-banded cockroach.

Easy to mix up

• Mouse droppings look like grains of rice, pointed at the ends, scattered along walls and inside cupboards, often with gnawed packets nearby. Rat droppings are much larger. See mice and rats.
• Termite droppings from drywood termites are hard, tiny pellets, all much the same size, often in a small pile below a pinhole in wood, a bit like sand. Termites are not found everywhere, so if you suspect them in furniture or the structure of the house, ask a local pest controller to look.
• Dark spots on mattress seams and small blood marks on sheets point to bed bugs, not cockroaches.

Context counts. Specks at the back of a wooden cupboard a week after you saw German cockroaches are most likely theirs. Hard, even pellets spilling out of holes in the wood are worth a professional’s eye.

Egg cases and shed skins

• Egg cases are brown capsules, ridged like a tiny purse. Small ones in kitchens and bathrooms are German. Ones glued under shelves and inside drawers point to brown-banded. Larger, darker ones dropped in damp, sheltered corners come from American or oriental cockroaches. An empty case that is split open has usually hatched.
• A capsule that does not quite fit, much bigger than you expect, smooth rather than ridged, or found where you have never seen a cockroach, may be something else entirely. Photograph it next to a coin and compare it with our droppings and egg cases guide before you worry.
• Shed skins are pale, papery and shaped like a cockroach. Young cockroaches shed their skin as they grow, so a skin means a young one grew somewhere close. One skin in the shower, in a building where neighbours have cockroaches, is a reason to put traps out, not proof of an infestation on its own.

What each sign means for your plan

1. Traps go where the signs are thickest. Set monitor traps flat against the wall right beside them, and check them on the same day each week.
2. Clean it up, then watch. New specks on a clean hinge mean something is active now. Old droppings left by a previous occupant will not come back.
3. Egg cases or shed skins mean breeding. For German or brown-banded cockroaches, that is when bait and a growth regulator come in. See found baby cockroaches for the order.
4. Do not spray the spot. It pushes them deeper and spoils bait you may need there.

Cleaning up safely: wear gloves, wipe or vacuum rather than sweeping dust into the air, and wash your hands after. Cockroach droppings and shed skins can trigger asthma and allergies in some people. If anyone at home has breathing trouble, see a doctor or pharmacist. More in cockroaches and asthma.

You can scan droppings and egg cases as well as the insect itself, and Shoo says “not sure” when the photo cannot settle it. A clear photo and the place you found it get you most of the way. If you think you have termites or rats, call a professional rather than treating alone.