Record the clue before interpreting it
Use phone magnification and a ruler. Note hairs, segmentation, legs, antennae, tail filaments and whether the skin is intact.
A useful record includes scale, shape, texture, placement and whether the material returns after a clean baseline is established. Avoid changing the scene merely to make identification easier.
What to note
- Hairy or smooth surface
- Visible legs and antennae
- Body segmentation
- Concentration along seams or harborages
Avoid handling skins associated with contaminated bedding or extensive infestation; isolate the item before moving it.
Read the full safety guideCommon candidates
These candidates are not ranked until location, scale, pattern, context and timing are added. Open a profile to see confirming and contradicting evidence.
Bed bug
Cimex lectularius
Ink-like fecal spots, pale cast skins, eggs and flat reddish insects concentrated along bed or furniture seams.
German cockroach
Blattella germanica
Pepper-like spotting, small ridged egg cases and nighttime activity clustered near food, water and heat.
Varied carpet beetle
Anthrenus verbasci
Hairy banded larval skins and irregular grazing damage in lint, wool, feathers or stored natural fibers.
Clothes moth
Tineola bisselliella and Tinea pellionella
Smooth pale larvae, attached silk cases or webbing and clipped natural fibers in dark garment folds.
Silverfish
Lepisma saccharinum
Silvery tapered body, three tail filaments and irregular surface grazing in cool humid paper or storage areas.
Firebrat
Thermobia domestica
Mottled tapered insect with three tail filaments recurring near a hot, humid appliance or boiler zone.
Comparisons that resolve common confusion
Side-by-side decision
Mouse vs. cockroach droppings
Size and surface are the fastest split: mouse droppings are distinct rice-like pieces; German-cockroach evidence is usually pepper-like spotting or tiny ridged material.
Open comparison
Side-by-side decision
German vs. American cockroach evidence
German cockroaches cluster in warm indoor harborages; American cockroaches are far larger and often travel from humid utility or drain systems.
Open comparison
Side-by-side decision
German vs. Oriental cockroach evidence
Temperature and level separate them: German cockroaches favor warm appliance voids; Oriental cockroaches favor cool damp lower spaces.
Open comparison
Side-by-side decision
Bed bug vs. carpet beetle cast skins
Bed-bug skins preserve a flat insect outline with legs; carpet-beetle skins are hairy and often banded.
Open comparison
Side-by-side decision
Bed bugs vs. fleas
Bed bugs leave seam-centered eggs, skins and spotting; fleas jump and center on animal resting zones with flea dirt.
Open comparison
Side-by-side decision
Carpet beetle vs. clothes moth damage
Carpet beetles leave hairy skins; clothes moths leave attached silk, tubes or cases.
Open comparison