1.there are some signs you can look out for around your home. Firstly, look for blood spots on your clothing, mattress and bedding. 2. keep an eye out for bed bug excrement. Again, these are tiny marks, but these are dark brown. You’ll be able to identify them as they’ll bleed a little as they run through materials as a marker pen would. 3. Another way to spot bed bugs is from their eggs. Bed bug eggs and eggshells are only about 1mm at first, but grow larger. Their pale yellow colour can identify the eggs.